Camptothecin derivatives as chemoradiosensitizing agents

ABSTRACT

Camptothecin-based compounds are useful for treating a neoplasm in mammalian subjects by administering such compound to the subjects in combination with radiotherapy, i.e., the treatment of tumors with radioactive substances or radiation from a source external to the subject. Camptothecin-based compounds are modified by positioning at least one electron-affinic group around the camptothecin structure to enhance their value in combination with radiotherapy. New Camptothecin-based compounds are disclosed that are useful for treating cancer by administering the novel compounds alone or in combination with radiotherapy.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of the provisional U.S. Application Ser.No. 60/728,924, filed 21 Oct. 2005, incorporated herein by reference inits entirety.

INTRODUCTION

1. Field of the Invention

The present invention relates generally to using certaincamptothecin-based compounds that are useful for treating variouscancers, particularly in combination with radiotherapy.

2. Background of the Invention

Cancer is the second leading cause of death in the U.S. and accounts forthe deaths of 1 of every 4 Americans. The American Cancer Societyestimates that 556,000 Americans died from cancer in 2003. Cancertherapy is presently based on three different approaches, namelychemotherapy, radiation therapy (i.e. radiotherapy) and surgery.Radiotherapy is often used as adjuvant or secondary treatment followingsurgical procedures to remove a cancerous tumor or in combination withchemotherapy.

The radiotherapeutic approach to eradicating malignant cells found incancerous tumors was first introduced during the late 1800s and iscurrently used with curative intent or for palliation in approximatelyhalf of all cancer patients. Radiotherapy remains a component of thestandard of care for most locally advanced solid tumors. Localrecurrence remains a major obstacle to achieving cure of many locallyadvanced solid tumors treated with definitive radiation therapy. Thislocal recurrence translates directly into poor likelihood of long-termsurvival.

The ability of radiation therapy to eradicate malignant cells criticallydepends upon the intratumoral content of molecular oxygen, a potentradiosensitizer involved in mediating DNA damage. The microenvironmentof solid tumors is hypoxic compared with normal tissue, and this hypoxiais associated with decreased radiosensitivity. Recent preclinical datasuggest that intratumoral hypoxia, particularly in conjunction with anacid microenvironment, may be directly or indirectly mutagenic.Investigations of the prognostic significance of the pretreatmentoxygenation status of tumors in patients with head and neck or cervicalcancer have demonstrated that increased hypoxia, typically designated inthese studies as pO₂ levels below 2.5-10 mm Hg, is associated withdecreased local tumor control and higher rates of disease and loweroverall survival. Hypoxia-directed therapies in the radiation oncologysetting include treatment using hyperbaric oxygen, fluosol infusion,carbogen breathing, and electron-affinic and hypoxic-cell sensitizers.

The most well-studied, hypoxia-directed strategy for cancer treatment isthe use of electron-affinic radiosensitizers, which mimic the actions ofoxygen but are more slowly metabolized. During the past 2 decades, thenitroimidazole compounds misonidazole, nimorazole, and etanidazole havebeen extensively evaluated by the Radiation Therapy Oncology Group(RTOG) and the Danish Association of Head and Neck Cancer (DAHANCA) asadjuncts to radiation therapy in carcinomas of the head and neck,cervix, and lung (Grigsby et al. Int J Radiat Oncol Biol Phys 1999;44:513-517; Lee et al. Int J Radiat Oncol Biol Phys 1989; 16:465-470;Lee et al. Int J Radiat Oncol Biol Phys 1995; 32:567-576; Overgaard etal. Int J Radiat Oncol Biol Phys 1989; 16:1069-1072; Overgaard et al.Int J Radiat Oncol Biol Phys 1989; 16:1065-1068; Overgaard Int J RadiatBiol 1989; 56:801-811; Overgaard et al. Radiother Oncol 1998;46:135-146; Wasserman et al. Radiother Oncol 1991; 20(suppl 1):129-135.Most of these studies reported disappointing local control and survivaloutcomes, but a few recent studies appear to support the use ofnitroimidazole compounds with radiation therapy. Other cancer treatmentprotocols currently employ radiosensitizers activated by ionizingradiation, e.g., X-rays. Examples of X-ray-activated radiosensitizersinclude, but are not limited to, the following: metronidazole,desmethylmisonidazole, pimonidazole, mitomycin C, RSU 1069, SR 4233,E09, RB 6145, nicotinamide, 5-bromodeoxyuridine(BUdR),5-iododeoxyuridine (IUdR), bromodeoxycytidine, fluorodeoxyuridine(FUdR), hydroxyurea, cisplatin, and therapeutically effective analogsand derivatives of the same.

Some therapeutic compounds, which are known as being cytotoxic per se,hence susceptible of being used in the therapy of cancer, are alsoendowed with radiosensitization activity as they are capable of inducingDNA radiation damage in response to ionizing radiation. So far, thepossibility of combining both cytotoxic agents, e.g. a givenradiosensitizer and radiotherapy, with the expectation of getting asupra-additive antitumor effect in comparison to the single cytotoxicalone, is of utmost importance in cancer therapy. Among the severalcompounds endowed with antitumor activity and also known as possessingradiosensitization activity see, for instance, cisplatin, gemcitabine,navelbine, tomudex, nicotinamide, paclitaxel, docetaxel, simvastatin andtopotecan.

We have now discovered that the chemotherapeutic activity of certaincamptothecin (CPT) derivatives is enhanced by appending variouselectronic-affinic groups to provide a single compound for use as achemoradiosensitizer. The compounds of the invention are considerablyless toxic than camptothecin and topotecan. This invention defines a newseries of radiosensitizing camptothecin derivatives that are useful fortreating various types of cancer. We have also discovered that certainknown CPT derivatives are useful in the process of sensitizing asubject's tumor cells to radiation, wherein the process comprisesadministering a CPT derivative to a subject and then exposing the tumorcells in the subject to radiation.

SUMMARY OF THE INVENTION

One aspect of the invention provides methods of sensitizing tumor cellsin a subject to radiation, said method comprising a) administering tothe subject in need thereof a camptothecin-based compound comprising oneor more radiosensitizing electron-affinic groups; and b) exposing thetumor cells in the subject to a unit dose of radiation.

Another aspect of the invention provides methods of sensitizing tumorcells to radiation, said method comprising: a) administering to a humanor animal subject in need thereof a compound or a pharmaceuticallyacceptable salt thereof having formula (I), below, and b) exposing thesubject to a unit dose of ionizing radiation. Preferably, steps a) andb) are applied according to a treatment schedule effective to produce asynergistic anti-neoplastic effect.

-   -   wherein W is alkyl-C(O)—, or R¹Y-L-C(O)—, provided that when W        is alkyl-C(O)—, at least one of R², R³, R⁴, R⁵, or R⁶ is nitro;    -   L is a bond or linear alkylene (1-8) group, optionally        substituted with lower alkyl or substituted lower alkyl, wherein        one or two methylene (—CH₂—) units of the linear alkylene group        is optionally replaced with O, S or NH;    -   Y is ═NO—, —N(H)O—, ═N—, —NR—, O, S, or a bond;    -   R is H, alkyl, or substituted alkyl;    -   R¹ is optionally substituted carbocyclic, heterocyclic, or fused        2-, 3- or 4-ring heterocyclic;    -   R² is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y, R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower        alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, tri lower alkylsilyl, lower alkylcarbonyloxy,        lower alkoxycarbonyloxy, sugar, phosphosugar, O-quinone,        substituted lower alkyl aminomethyl, lower alkylcarbonylamino,        lower alkylcarbonyloxy methyl, optionally substituted lower        alkylcarbonyloxy methyl, substituted vinyl,        1-hydroxy-2-nitroethyl, alkoxycarbonylethyl, aminocarbonyl,        alkylcarbonyl, benzoylmethyl, benzylcarbonyloxymethyl, lower        alkyliminomethyl or lower alkoxymethyl;    -   R³ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, CH₂NR⁷R⁸ (where each of R⁷ and R⁸ is        independently H, alkyl of 1-6 carbons, optionally substituted        phenyl, hydroxy lower alkyl, amino lower alkyl, or mono- or        dialkylamino lower alkyl, or R⁷ and R⁸ taken together with —N—        represent a cyclic amino-), CH₂R⁹ (where R⁹ is lower alkoxy,        cyano, amino lower alkoxy, mono- or di-lower alkylamino lower        alkoxy, lower alkylthio, amino lower alkylthio, or mono- or        di-lower alkylamino lower alkylthio), NR¹⁰R¹¹ (where each of R¹⁰        and R¹¹ is independently hydrogen, lower alkyl, phenyl, hydroxy        lower alkyl, or amino lower alkyl, or R¹⁰ and R¹¹ taken together        with —N— represent a cyclic amino), trialkylsilyl, dialkylamino        alkyl, lower alkylcarbonyloxy, lower alkoxycarbonyloxy, sugar,        phosphosugar, O-quinone, substituted lower alkyl aminomethyl, or        lower alkylcarbonylamino or R³ together with R⁴ is furan,        dihydrofuran or 1,4-oxazine-2-one; and    -   R⁴ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, amino lower alkyl,        halogenated lower alkyl, halogenated lower alkoxy,        hydroxycarbonyl, formyl, lower alkoxycarbonyl, carbamoyloxy,        lower alkylcarbonyloxy, lower alkoxycarbonyloxy, sugar,        phosphosugar, O-quinone, substituted lower alkyl aminomethyl, or        lower alkylcarbonylamino, or R⁴ together with R³ is furan,        dihydrofuran or 1,4-oxazine-2-one, or R⁴ together with R⁵ is        methylenedioxy;    -   R⁵ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, trialkylsilyl, halogenated        lower alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl,        lower alkoxycarbonyl, lower alkylcarbonyloxy, lower        alkoxycarbonyloxy, sugar, phosphosugar, O-quinone, substituted        lower alkyl aminomethyl, or lower alkylcarbonylamino, or R⁵        together with R⁴ is methylenedioxy;    -   R⁶ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, lower alkylcarbonyloxy, lower alkoxycarbonyloxy,        sugar, phosphosugar, O-quinone, substituted lower alkyl        aminomethyl, or lower alkylcarbonylamino; and    -   R^(Q) is optionally substituted carbocyclic, heterocyclic, or        fused 2-, 3- or 4-ring heterocyclic.

Another aspect of the invention provides compounds of formula (II),below:

wherein

-   -   X is a O, S, —NR—, or a covalent bond;    -   Y is ═NO—, —N(H)O—, ═N—, —NR—, O, S, or a covalent bond;    -   T is independently CRR′;    -   each of R and R′ is independently selected from hydrogen,        alkyl₁₋₄, and substituted alkyl₁₋₄;    -   n is an integer from 0 to 8;    -   R¹ is optionally substituted carbocyclic, heterocyclic, or fused        2-, 3- or 4-ring heterocyclic;        -   provided that when X is a bond, Y is ═NO—, —N(H)O—, ═N— or            S;    -   R² is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, tri lower alkylsilyl, lower alkylcarbonyloxy,        lower alkoxycarbonyloxy, sugar, phosphosugar, O-quinone,        substituted lower alkyl aminomethyl, lower alkylcarbonylamino,        lower alkylcarbonyloxy methyl, optionally substituted lower        alkylcarbonyloxy methyl, substituted vinyl,        1-hydroxy-2-nitroethyl, alkoxycarbonylethyl, aminocarbonyl,        alkylcarbonyl, alkylcarbonyloxymethyl, benzoylmethyl,        benzylcarbonyloxymethyl, lower alkyliminomethyl or lower        alkoxymethyl;    -   R³ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, CH₂NR⁷R⁸ (where each of R⁷ and R⁸ is        independently H, alkyl of 1-6 carbons, optionally substituted        phenyl, hydroxy lower alkyl, amino lower alkyl, or mono- or        dialkylamino lower alkyl, or R⁷ and R⁸ taken together with —N—        represent a cyclic amino-), CH₂R⁹ (where R⁹ is lower alkoxy, CN,        amino lower alkoxy, mono- or di-lower alkylamino lower alkoxy,        lower alkylthio, amino lower alkylthio, or mono- or di-lower        alkylamino lower alkylthio), NR¹⁰R¹¹ (where each of R¹⁰ and R¹¹        is independently hydrogen, lower alkyl, phenyl, hydroxy lower        alkyl, or amino lower alkyl, or R¹⁰ and R¹¹ taken together with        —N— represent a cyclic amino), trialkylsilyl, dialkylamino        alkyl, lower alkylcarbonyloxy, lower alkoxycarbonyloxy, sugar,        phosphosugar, O-quinone, substituted lower alkyl aminomethyl, or        lower alkylcarbonylamino or R³ together with R⁴ is furan,        dihydrofuran or 1,4-oxazine-2-one;    -   R⁴ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, amino lower alkyl,        halogenated lower alkyl, halogenated lower alkoxy,        hydroxycarbonyl, formyl, lower alkoxycarbonyl, carbamoyloxy,        lower alkylcarbonyloxy, lower alkoxycarbonyloxy, sugar,        phosphosugar, O-quinone, substituted lower alkyl aminomethyl, or        lower alkylcarbonylamino, or R⁴ together with R³ is furan,        dihydrofuran or 1,4-oxazine-2-one, or R⁴ together with R⁵ is        methylenedioxy;    -   R⁵ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, lower alkylcarbonyloxy, lower alkoxycarbonyloxy,        sugar, phosphosugar, O-quinone, substituted lower alkyl        aminomethyl, or lower alkylcarbonylamino;    -   R⁶ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, trialkylsilyl, halogenated        lower alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl,        lower alkoxycarbonyl, lower alkylcarbonyloxy, lower        alkoxycarbonyloxy, sugar, phosphosugar, O-quinone, substituted        lower alkyl aminomethyl, or lower alkylcarbonylamino;    -   L is a bond or linear alkylene (1-8) group, optionally        substituted with lower alkyl or substituted lower alkyl, wherein        one or two methylene (—CH₂—) units of the linear alkylene group        is optionally replaced with O, S or NH; and    -   R^(Q) is optionally substituted carbocyclic, heterocyclic, or        fused 2-, 3- or 4-ring heterocyclic.

Another aspect of the invention provides pharmaceutical compositionscomprising a compound of formula (I) or (II) as defined above, togetherwith a pharmaceutically acceptable excipient. The invention alsoprovides methods for treating a cancer disorder in a subject having atumor comprising administering to the human or animal subject such apharmaceutical composition. In a preferred embodiment, this methodfurther comprising exposing the tumor in the subject to a unit dose ofradiation.

Another aspect of the invention provides method of treating a neoplasmcomprising: a) administering to a human or animal subject in needthereof a compound or a pharmaceutically acceptable salt thereof havingformula (I), as defined above, and b) exposing the subject to a unitdose of ionizing radiation.

Other aspects of this invention will be apparent to one of skill in theart by reviewing the ensuing specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph depicting in vivo chemoradiosensitizing effect ofcompound 13 on MTG-B mouse mammary adenocarcinoma tumors, as describedin Example 14.

FIG. 2 is a graph depicting in vitro chemotherapeutic activity ofcompound 13 on MCF-7 human breast cancer cells, as described in Example15.

FIG. 3 is a graph depicting the maximum tolerated dose (MTD) of compound13, topotecan, camptothecin and cisplatin, as described in Example 16.

DETAILED DESCRIPTION 1. Overview

There are several aspects to this invention. One is based on thediscovery that certain known camptothecin-based compounds are useful fortreating a neoplasm in mammalian subjects by administering such compoundto the subjects in combination with radiotherapy, i.e., the treatment oftumors with radioactive substances or radiation from a source externalto the subject. Another aspect is based on the discovery thatcamptothecin-based compounds can be modified by positioning at least oneelectron-affinic group around the camptothecin structure to enhancetheir value in combination with radiotherapy. Another aspect of theinvention is based on the discovery of certain novel compounds that areuseful for treating cancer by administering the novel compounds alone orin combination with radiotherapy. These discoveries lead to otheraspects of the invention discussed hereinafter.

2. Definitions

The term “radiosensitizer” refers to a compound or medicament which iscapable of increasing the sensitivity of a tumor cell to ionizingradiation, thus improving the likelihood of tumor cell destruction uponexposure to such radiation.

The term “ionizing radiation” is the one conventionally adopted in thetherapeutic field of cancer treatment and includes photons having enoughenergy for chemical bond ionization such as, for instance, α, β and γrays (also known as alpha, beta, and gamma rays) from radioactive nucleias well as x-rays. The radiation may be high-LET (linear energytransfer) or low-LET. LET is the energy transferred per unit length ofthe distance. High LET is said to be densely ionizing radiation and LowLET is said to be sparsely ionizing radiation. Representative examplesof high-LET are neutrons and a particles. Representative examples oflow-LET are x-ray and γ rays. Low LET radiation including both x-raysand γ rays is most commonly used for radiotherapy of cancer patients.The radiation may be used for external radiation therapy that is usuallygiven on an outpatient basis or for internal radiation therapy that usesradiation that is placed very close to or inside the tumor. In case ofinternal radiation therapy, the radiation source is usually sealed in asmall holder called an implant. Implants may be in the form of thinwires, plastic tubes called catheters, ribbons, capsules, or seeds. Theimplant is put directly into the body. Internal radiation therapy mayrequire a hospital stay. The ionizing radiation source is provided as aunit dose of radiation and is preferably an x-ray tube since it providesmany advantages, such as convenient adjustable dosing where the sourcemay be easily turned on and off, minimal disposal problems, and thelike. A unit dose of radiation is generally measured in gray (Gy). Theionizing radiation source may also comprise a radioisotope, such as asolid radioisotopic source (e.g., wire, strip, pellet, seed, bead, orthe like), or a liquid radioisotopic filled balloon. In the latter case,the balloon has been specially configured to prevent leakage of theradioisotopic material from the balloon into the body lumen or bloodstream. Still further, the ionizing radiation source may comprise areceptacle in the catheter body for receiving radioisotopic materialslike pellets or liquids. The radioisotopic material may be selected toemit α, β and γ radiation. Usually, α and β radiation are preferredsince they may be quickly absorbed by surrounding tissue and will notpenetrate substantially beyond the wall of the body lumen being treated.Accordingly, incidental irradiation of the heart and other organsadjacent to the treatment region can be substantially eliminated. Thetotal number of units provided will be an amount determined to betherapeutically effective by one skilled in treatment using ionizingradiation. This amount will vary with the subject and the malignantcells or neoplasm being treated. The amount may vary but a patient mayreceive a dosage of about 30-75 Gy over several weeks.

The term “anti-neoplastic effect” refers to inhibiting or retarding thegrowth of a malignant cell, or in the case of a subject having amalignant tumor, the rate of tumor growth is decreased, the volume ofsuch tumor is reduced, or the tumor is eliminated entirely.

The term “electron-affinic” refers to an attraction a moiety has forelectrons that causes the affinic moiety to enter into and remain inchemical combination with one or more electrons. Typically anelectron-affinic moiety is chemically reducible (i.e. an oxidizinggroup). Representative electron affinic moieties are presented herein.

“Synergistic,” as used herein, means that the therapeutic results fromtreatment of a neoplasm in a subject with (i) a radiosensitizer incombination with (ii) ionizing radiation are improved over what would beobtained by summing the results of (i) alone with (ii) alone. Theimprovement may be better anti-neoplastic effect or other beneficialresults.

The term “CPT” is an abbreviation for camptothecin, also known as(S)-4-ethyl-4-hydroxy-1H-pyrano-[3′,4′:6,7]indolizino[1,2-b]quinoline-3,14(4H,12H)-dione. The compound isreadily available from numerous sources, e.g., Sigma Chemical Co., St.Louis, Mo. The chemical formula of camptothecin and its numbering systemare as follows:

In the structure above and in the rest of the application the wedgedbond (for example, the bond showing attachment of hydroxyl group at C20)indicates its attachment to a chiral carbon and is coming out of theplane. Analogously, a dotted bond indicates its attachment to a chiralcarbon and it is going into the plane. The compound has a hydroxy at the20-position that is esterified to make the compounds of this invention.

The term “alkyl” refers to a monovalent, saturated aliphatic hydrocarbonradical having the indicated number of carbon atoms. For example, a “C1-6 alkyl” or an “alkyl of 1-6 carbons” or “Alk 1-6” would refer to anyalkyl group containing one to six carbons in the structure. “C 1-20alkyl” refers to any alkyl group having one to twenty carbons. Alkyl maybe a straight chain (i.e. linear) or a branched chain. Lower alkylrefers to an alkyl of 1-6 carbons. Representative examples of loweralkyl radicals include methyl, ethyl, n-propyl, n-butyl, n-pentyl,n-hexyl, isopropyl, isobutyl, isopentyl, amyl, sec-butyl, tert-butyl,tert-pentyl and the like. Higher alkyl refers to alkyls of seven carbonsand above. These include n-heptyl, n-octyl, n-nonyl, n-decyl, n-dodecyl,n-tetradecyl, n-hexadecyl, n-octadecyl, n-eicosyl, and the like, alongwith branched variations thereof. The radical may be optionallysubstituted with substituents at positions that do not significantlyinterfere with the preparation of compounds falling within the scope ofthis invention and that do not significantly reduce the efficacy of thecompounds. The alkyl is optionally substituted with one to fivesubstituents independently selected from the group consisting of halo,lower alkoxy, hydroxy, cyano, nitro, phenyl, amino, halogenated loweralkyl, halogenated lower alkoxy, hydroxycarbonyl, lower alkoxycarbonyl,lower alkylcarbonyloxy, and lower alkylcarbonylamino.

The term “Alkylene” refers to divalent saturated aliphatic hydrocarbylgroups preferably having from 1 to 8 carbon atoms that are eitherstraight-chained (linear) or branched. This term is exemplified bylinear groups such as methylene (—CH₂—), ethylene (—CH₂CH₂—),n-propylene (—CH₂CH₂CH₂—) and branched groups such as iso-propylene(—CH₂CH(CH₃)—) or (—CH(CH₃)CH₂—) and the like.

The term “alkoxy” refers to a monovalent radical of the formula RO—,where R is an alkyl as defined herein. Lower alkoxy refers to an alkoxyof 1-6 carbon atoms, with higher alkoxy is an alkoxy of seven or morecarbon atoms. Representative lower alkoxy radicals include methoxy,ethoxy, n-propoxy, n-butoxy, n-pentyloxy, n-hexyloxy, isopropoxy,isobutoxy, isopentyloxy, amyloxy, sec-butoxy, tert-butoxy,tert-pentyloxy, and the like. Higher alkoxy radicals include thosecorresponding to the higher alkyl radicals set forth herein. The radicalmay be optionally substituted with substituents at positions that do notsignificantly interfere with the preparation of compounds falling withinthe scope of this invention and that do not significantly reduce theefficacy of the compounds. The alkoxy is optionally substituted with oneto five substituents independently selected from the group consisting ofhalo, lower alkyl, lower alkoxy, hydroxy, cyano, nitro, phenyl, amino,halogenated lower alkyl, halogenated lower alkoxy, hydroxycarbonyl,lower alkoxycarbonyl, lower alkylcarbonyloxy, and loweralkylcarbonylamino.

The term “cycloalkyl” refers to a monovalent, alicyclic, saturatedhydrocarbon radical having three or more carbons forming the ring. Whileknown cycloalkyl compounds may have up to 30 or more carbon atoms,generally there will be three to seven carbons in the ring. The latterinclude, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,and cycloheptyl. The radical may be optionally substituted withsubstituents at positions that do not significantly interfere with thepreparation of compounds falling within the scope of this invention andthat do not significantly reduce the efficacy of the compounds. Thecycloalkyl is optionally substituted with one to five substituentsindependently selected from the group consisting of halo, lower alkyl,lower alkoxy, hydroxy, cyano, nitro, phenyl, amino, halogenated loweralkyl, halogenated lower alkoxy, hydroxycarbonyl, lower alkoxycarbonyl,lower alkylcarbonyloxy, and lower alkylcarbonylamino.

The term “hydroxycarbonyl” is a monovalent radical having the formula—C(O)OH.

The term “lower alkoxycarbonyl” is a monovalent radical having theformula —C(O)OAlk, where Alk is lower alkyl.

The term “lower alkoxycarbonyloxy” is a monovalent radical having theformula —OC(O)OAlk, where Alk is lower alkyl.

The term “sugar” refers to a monovalent radical formed by removal of ahydrogen from any hydroxy group of a monsaccharide, disaccharide,oligosaccharide or polysaccharide. The monosaccharide unit that is apart of a disaccharide, oligosaccharide or polysaccharide may be a D orL isomer existing as a five-membered cyclic form (furanose) or a6-membered cyclic form (pyranose). Representative examples ofmonosaccharides include glucose, fructose, mannose, and galactose.Representative examples of disaccharides include lactose, maltose, andsucrose. Oligosaccharides may contain 3-20 monosaccharide units linkedtogether, more preferably 3-15 monosaccharide units linked together.Representative examples of oligosaccharides include maltotetraose andcyclodextrin. Representative examples of polysaccharides includeamylase, starch and cellulose.

The term “phosphosugar” refers to a monovalent radical formed by removalof a hydrogen from any hydroxy group of either a monsaccharide or aphosphoric acid wherein the monosaccharide is linked to the phosphoricacid via an ether linkage. The monosaccharide may be a D or L isomerexisting as a five-membered cyclic form (furanose) or a 6-memberedcyclic form (pyranose). Representative examples of monosaccharides areset forth above.

The term “lower alkylcarboxyloxy” is a monovalent radical having theformula —OC(O)Alk, where Alk is lower alkyl.

The term “lower alkylcarbonylamino” is a monovalent radical having theformula —NHC(O)Alk, where Alk is lower alkyl.

The term “substituted lower alkyl aminomethyl” is a monovalent radicalhaving the formula —CH₂NHAlk, where Alk is a substituted lower alkyl.Representative examples of substituted lower alkyl aminomethyl include(tris(hydroxymethyl)methylamino)methyl,(bis(hydroxymethyl)methylamino)methyl, and (2-hydroxyethylamino)methyl.

A “halo” substitutent is a monovalent halogen radical chosen fromchloro, bromo, iodo, and fluoro. A “halogenated” compound is onesubstituted with one or more halo substituents. Chloro is generallypreferred.

A “1-naphthyl” or “2-naphthyl” is a radical formed by removal of ahydrogen from the 1- or 2-position of a naphthalene structure,respectively. It is optionally substituted with from one to foursubstituents independently selected from the group consisting of halo,lower alkyl, lower alkoxy, hydroxy, cyano, nitro, phenyl, amino,halogenated lower alkyl, formyl, halogenated lower alkoxy,hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyloxy, and loweralkylcarbonylamino.

A “phenyl” is a radical formed by removal of a hydrogen from a benzenering. The phenyl is optionally substituted with from one to fivesubstituents independently selected from the group consisting of halo,lower alkyl, lower alkoxy, hydroxy, cyano, nitro, amino, halogenatedlower alkyl, halogenated lower alkoxy, carbonyl, hydroxycarbonyl, loweralkylcarbonyloxy, benzyloxy, optionally substituted piperidino, loweralkoxycarbonyl, and lower alkylcarbonylamino.

A “cyclic amino” is a monovalent radical of a saturated 5-, 6-, or7-membered cyclic amine ring having no more than one additional heteroatom such as nitrogen, oxygen, or sulfur. Representative examplesinclude, e.g., 1-pyrrolidino, 1-piperidino, morpholino, piperazino, andthe like. These may be substituted or unsubstituted. If substituted,generally they will have no more than 2 substituents chosen from loweralkyl, lower cycloalkyl, hydroxy lower alkyl, phenyl (substituted orunsubstituted), benzyl (substituted or unsubstituted),aminocarbonylmethyl, lower alkylaminocarbonylmethyl, amino, mono- ordi-lower alkylamino, or cyclic amino.

“Monovalent radical” refers to attachment of the radical via a singlebond.

“Divalent radical” refers to attachment of the radical via a doublebond.

“Heteroatom” refers to nitrogen, oxygen, sulfur, or any oxidized form ofnitrogen or sulfur.

“Cyano” refers to a monovalent —CN radical.

“Nitro” refers to a monovalent —NO₂ radical.

“Amino” refers to a monovalent —NH₂ radical.

“Formyl” refers to a monovalent —CHO radical.

“Tri loweralkylsilyl” refers to a monovalent silyl radical substitutedwith three loweralkyl groups, where the lower alkyl groups may be thesame or different.

“Loweralkylcarbonyloxy methyl” refers to a monovalent —CH₂C(O)(loweralkyl) radical.

“Substitued vinyl” refers to a substituted —CH═CH₂ group were one ormore the CH groups are replaced with one to three substituentsindependently selected from the group consisting of alkyl, halo, loweralkoxy, hydroxy, cyano, nitro, phenyl, amino, halogenated lower alkyl,halogenated lower alkoxy, hydroxycarbonyl, lower alkoxycarbonyl, loweralkylcarbonyloxy, and lower alkylcarbonylamino.

“Hydroxy” refers to a monovalent OH radical.

“Carbocyclic” refers to a 3-18 membered ring monovalent or divalentradical where all the ring atoms are carbon and may be fully saturated,partially saturated, or unsaturated (i.e. aromatic in nature). Thecarbocyclic radical is bonded through a saturated, partially saturated,or unsaturated ring via a single or double bond. Carbocyclic groups maybe fused, containing 2, 3, or 4 rings where the fused rings areindependently saturated, partially saturated, or unsaturated. Examplesof carbocyclic groups include phenyl, naphthyl, fluorenyl, andtetracenyl. The radical may be optionally substituted with substituentsat positions that do not significantly interfere with the preparation ofcompounds falling within the scope of this invention and that do notsignificantly reduce the efficacy of the compounds. The radical isoptionally substituted with one to five substituents independentlyselected from the group consisting of halo, lower alkyl, lower alkoxy,hydroxy, cyano, nitro, amino, halogenated lower alkyl, halogenated loweralkoxy, hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyloxy,lower alkylcarbonylamino, sugar and phosphosugar.

A “carbamoyloxy” is a monovalent radical of the formula R₁₃R₁₄NC(O)O—(i.e. an aminocarbonyloxy) where R₁₃ and R₁₄ together form a cyclicamino with the nitrogen atom, or each of R₁₃ and R₁₄ is independentlyhydrogen, lower alkyl, hydroxy lower alkyl, amino lower alkyl, lowercycloalkyl, phenyl (substituted or unsubstituted), or benzyl(substituted or unsubstituted). Examples include aminocarbonyloxy,methylaminocarbonyloxy, dimethyl aminocarbonyloxy,[4-(1-piperidino)-1-piperidino]carbonyloxy, 1-morpholinocarbonyloxy,1-pyrrolidinyl, 1-piperazinecarbonyloxy, and others recognized by oneskilled in the art or delineated herein.

“Heterocyclic” is a monovalent or divalent radical of a 3-10 memberedring group containing at least one heteroatom in the ring and may befully saturated, partially saturated, or unsaturated (i.e. aromatic innature). The heterocycle is bonded through a carbon atom or heteroatomvia a single or double bond. The heteroatom in the heterocycle such as Ncan optionally exist as an N-oxide or S can optionally exist as asulfoxide or a sulfone.

A “5-membered heterocyclic ring” is a monovalent or a divalent radicalof a 5-membered ring containing at least one heteroatom in the ring andmay be fully saturated, partially saturated, or unsaturated (i.e.aromatic in nature). Generally the heterocycle will contain no more thantwo hetero atoms. The heterocycle is bonded through a carbon atom orheteroatom via a single or double bond. Representative examples ofunsaturated 5-membered heterocycles with only one hetero atom include 2-or 3-pyrrolyl, 2- or 3-furanyl, and 2- or 3-thiophenyl. Correspondingpartially saturated or fully saturated radicals include 3-pyrrolin-2-yl,2- or 3-pyrrolidinyl, 2- or 3-tetrahydrofuranyl, and 2- or3-tetrahydrothiophenyl. Representative unsaturated 5-memberedheterocyclic radicals having two hetero atoms include imidazolyl,oxazolyl, thiazolyl, pyrazolyl, and the like. The corresponding fullysaturated and partially saturated radicals are also included. Theradical may be optionally substituted with substituents at positionsthat do not significantly interfere with the preparation of compoundsfalling within the scope of this invention and that do not significantlyreduce the efficacy of the compounds. The ring is optionally substitutedwith one or two substituents selected from the group consisting of halo,lower alkyl, lower alkoxy, hydroxy, cyano, nitro, phenyl, amino,halogenated lower alkyl, halogenated lower alkoxy, hydroxycarbonyl,lower alkoxycarbonyl, lower alkylcarbonyloxy, lower alkylcarbonylamino,sugar and phosphosugar.

A “6-membered heterocyclic ring” is a monovalent or a divalent radicalof a 6-membered ring containing at least one heteroatom and may be fullysaturated, partially saturated, or unsaturated (i.e. aromatic innature). Generally the heterocycle will contain no more than two heteroatoms. The heterocycle is bonded through a carbon atom or heteroatom viaa single or double bond. Representative examples of unsaturated6-membered heterocycles with only one hetero atom include 2-, 3-, or4-pyridinyl, 2H-pyranyl, and 4H-pyranyl. Corresponding partiallysaturated or fully saturated radicals include 2-, 3-, or 4-piperidinyl,2-, 3-, or 4-tetrahydropyranyl and the like. Representative unsaturated6-membered heterocyclic radicals having two hetero atoms include 3- or4-pyridazinyl, 2-, 4-, or 5-pyrimidinyl, 2-pyrazinyl, and the like. Thecorresponding fully saturated and partially saturated radicals are alsoincluded, e.g. 2-piperazine. The radical may be optionally substitutedwith substituents at positions that do not significantly interfere withthe preparation of compounds falling within the scope of this inventionand that do not significantly reduce the efficacy of the compounds. Thering is optionally substituted with one or two substituents selectedfrom the group consisting of halo, lower alkyl, lower alkoxy, hydroxy,cyano, nitro, phenyl, amino, halogenated lower alkyl, halogenated loweralkoxy, hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyloxy,lower alkylcarbonylamino, sugar and phosphosugar.

A “fused 2-3- or 4-ring heterocyclic” is a monovalent or a divalentradical that is polynuclear in that the adjacent rings share a pair ofatoms, generally carbon atoms. At least one of the rings will beheterocyclic in that it will have a noncarbon atom such as nitrogen,oxygen, or sulfur. The ring system may contain from 9 to 18 atoms. Theheterocycle is bonded through a carbon atom or heteroatom of one of therings via a single or double bond. A 2-ring heterocyclic system willgenerally have 9 or 10 atoms included in the ring. Examples of such a2-ring system include quinoline, isoquinoline, purine, indolizine,4H-quinolizine, 3H-pyrrolizine, coumaran, coumarin, isocoumarin,4-methylcoumarin, 3-chloro-H-methylcoumarin, chromone, benzofuran,benzothiophene, benzothiazole, indole, and the like. A 3-ring systemwill generally have 12 to 14 atoms included in the ring. Examples ofsuch a 3-ring system include carbazole, acridine, and the like. A 4-ringfused system will generally have 16 to 18 atoms included in the chain.Examples of such a 4-ring system include isothebaine and the like. Theradical may be optionally substituted with substituents at positionsthat do not significantly interfere with the preparation of compoundsfalling within the scope of this invention and that do not significantlyreduce the efficacy of the compounds. The radical is optionallysubstituted with one to five substituents independently selected fromthe group consisting of halo, lower alkyl, lower alkoxy, hydroxy, cyano,nitro, phenyl, amino, halogenated lower alkyl, halogenated lower alkoxy,hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyloxy, loweralkylcarbonylamino, sugar and phosphosugar.

Other chemical terms are given their standard meaning as understood byone of skill in the art with guidance from standard texts anddictionaries. Under standard nomenclature used throughout thisdisclosure, the terminal portion of the substituent is described first,followed by adjacent functionality toward the point of attachment. Thus,for example, a “aminocarbonyl” group refers to a —C(O)NH₂ group, a“loweralkoxymethyl” group refers to a —CH₂ (loweralkoxy) group, a “aminolower alkoxy” group refers to a -(loweralkoxy)amino group, etc.

3. Method of Treatment of the Invention

a. Types of Cancer Treated

This invention relates to the treatment of cancer. More specifically,the invention is directed to the treatment of a subject, particularly amammal such as a human, having a neoplasm by administering atherapeutically effective amount of a novel compound of formula (II) tothe subject for a period of time sufficient to produce ananti-neoplastic result. The treatment may optionally include the step ofdirecting ionizing radiation to the neoplasm. The neoplasm may also betreated by administering a CPT-based compound as described herein, andexposing the neoplasm to an effective amount of ionizing radiation, i.e.at least a unit dose.

The term cancer is to be considered in the broadest general definitionas a malignant neoplasm, an abnormal mass of tissue, the growth of whichexceeds and is uncoordinated with that of normal tissues and persists inthe same excessive manner after cessation of the stimuli that evoked thechange. It might be added that the abnormal mass is purposeless, preyson the host, and is virtually autonomous. A cancer can also beconsidered as a malignant tumor. A further discussion of neoplasia isfound at “Robbins Pathologic Basis of Disease,” Sixth Edition, by R. S.Cotran, V. Kumar, and T. Collins, Chapter 8 (W. B. Saunders Company).This information from Chapter 8 is incorporated herein by reference. Thefollowing Table 1 provides examples of the types of cancers, i.e.,malignant tumors or neoplasia that may be treated by administering acompound of this invention.

TABLE 1 Tissue of Origin Malignant Composed of One Parenchymal Cell TypeMesenchymal tumors Connective tissue and derivatives FibrosarcomaLiposarcoma Chondrosarcoma Osteogenic sarcoma Endothelial and relatedtissues Blood vessels Angiosarcoma Lymph vessels LymphangiosarcomaSynovium Synovial sarcoma Mesothelium Mesothelioma Brain coveringsInvasive meningioma Blood cells and related cells Hematopoietic cellsLeukemias Lymphoid tissue Malignant lymphomas Muscle SmoothLeiomyosarcoma Striated Rhabdomyosarcoma Epithelial tumors Stratifiedsquamous Squamous cell or epidermoid carcinoma Basal cells of skin oradnexa Basal cell carcinoma Epithelial lining Glands or ductsAdenocarcinoma Papillary carcinoma Cystadenocarcinoma Respiratorypassages Bronchogenic carcinoma Bronchial adenoma (carcinoid)Neuroectoderm Malignant melanoma Renal epithelium Renal cell carcinomaLiver cells Hepatocellular carcinoma Urinary tract epithelium(transitional) Transitional cell carcinoma Placental epithelium(trophoblast) Choriocarcinoma Testicular epithelium (germ cells)Seminoma Embryonal carcinoma More Than One Neoplastic Cell-Mixed Tumors,Usually Derived From One Germ Layer Salivary glands Malignant mixedtumor of salivary gland origin Breast Malignant cystosarcoma phyllodesRenal anlage Wilms tumor More Than One Neoplastic Cell Type Derived FromMore Than One Germ Layer-Teratogenous Totipotential cells in gonads orin Immature teratoma, embryonic rests teratocarcinoma

b. Treatment with Drug Alone

The novel compounds of the invention are thus useful in the treatment ofa neoplasm, e.g. leukemia and solid tumors, such as colon, colo-rectal,ovarian, mammary, prostate, lung, kidney and also melanoma tumors. Thedosage range adopted will depend on the route of administration and onthe age, weight and condition of the patient being treated. Thecompounds may be administered, for example, by the parenteral route, forexample, intramuscularly, intravenously or by bolus infusion.

As used herein, a patient or subject is a vertebrate having cancer orother diseases. Preferably, the subject is a warm-blooded animal,particularly a mammal which includes both human and non-human mammals.Examples of non-human mammals include but are not limited to farmanimals, such as cows, sheep, pigs, goats, horses, and llama, and pets,such as dogs and cats. More preferably, the subject is a human. Thecompounds are shown herein as Formula TI and are described in moredetail hereinafter. For this aspect of the invention, a therapeuticallyeffective amount of the compound is administered to a subject in needthereof for a period of time sufficient to obtain an antineoplasticeffect.

With mammals, including humans, the effective amounts can beadministered on the basis of body surface area. The interrelationship ofdosages varies for animals of various sizes and species, and for humans(based on mg/m² of body surface) is described by E. J. Freireichet al.,Cancer Chemother. Rep., 50(4):219 (1966). Body surface area may beapproximately determined from the height and weight of an individual(see, e.g., Scientific Tables, Geigy Pharmaceuticals, Ardsley, N.Y. pp.537-538 (1970)). A suitable dose range is from 1 to 1000 mg ofequivalent per m² body surface area of a compound of the invention, forinstance from 50 to 500 mg/m².

c. Treatment with Drug and Radiotherapy

Another aspect of this invention is a method of treating a neoplasm in asubject, which method comprises a) administering to the subject acompound of formula (I) as described herein, and b) exposing thesubject's neoplasm to ionizing radiation. The compound is generallyadministered in combination with pharmaceutically acceptable excipientin accordance with a treatment schedule.

As used herein, the term “treatment schedule” refers to the amount,order and timing in which the subject is administered acamptothecin-based compound and exposed to a unit dose of ionizingradiation. The drug administration and radiation exposure may notnecessarily be carried out sequentially. Radiation exposure can becarried out after a single dose or after multiple doses of acamptothecin-based compound in order to get the optimum results. For allof the administering routes, the exact timing of administration of thedosages as well as exposure to radiation can be varied to achieveoptimal results. Generally, if using Intralipid 20 as the carrier forthe CPT derivative, the actual dosage of CPT derivative reaching thepatient will be less. This is due to some loss of the CPT derivative onthe walls of the syringes, needles and preparation vessels, which isprevalent with the Intralipid 20 suspension. When a carrier, such ascottonseed oil is used, this above described loss is not so prevalentbecause the CPT derivative does not adhere as much to the surface ofsyringes, etc. One of skill in the art would routinely alter the amountsin view of such loss of drug to syringe walls, etc.

Another important feature of the method provided by the presentinvention relates to the relatively low apparent overall toxicity of theCPT derivatives administered in accordance with the teachings herein.Overall toxicity can be judged using various criteria. For example, lossof body weight in a subject over 10% of the initially recorded bodyweight (i.e., before treatment) can be considered as one sign oftoxicity. In addition, loss of overall mobility and activity and signsof diarrhea or cystitis in a subject can also be interpreted as evidenceof toxicity.

Another aspect of this invention is a method for treating cancer in awarm-blooded animal, which method comprises administering atherapeutically effective amount of a compound of the invention asdefined herein. A compound useful in this invention is administered toan appropriate subject in need of these compounds in a therapeuticallyeffective dose by a medically acceptable route of administration such asorally, parentally (e.g., intramuscularly, intravenously,subcutaneously, interperitoneally), transdermally, rectally, byinhalation and the like.

Another aspect of this invention is the use of a camptothecin-basedcompound, as identified herein, for the preparation of a pharmaceuticalfor the treatment of a neoplasm in a subject in combination withradiotherapy.

d. Sensitizing Cells

One aspect of the invention is a method of sensitizing tumor cells toradiation, said method comprising: a) administering to a human or animalsubject in need thereof a compound comprising a camptothecin derivativecomprising one or more radiosensitizing electron-affinic groups; and b)exposing said subject to a unit dose of radiation. In some embodiments,steps a) and b) are applied according to a treatment schedule effectiveto produce a synergistic anti-neoplastic effect. Preferably at least oneof the radiosensitizing electron-affinic groups is a nitro-substitutedcarbocyclic or a nitro-substituted heterocyclic aromatic moiety that isattached to the C5, C7, C9, C10, C11, C12 or C20 position of the CPT.The radio sensitizing compounds of the present invention are prepared bylinking the “electron-affinic group” to the C5, C7, C9, C10, C11, C12 orC20 carbons of the core of the camptothecin derivative. The length andnature of the linker between the camptothecin and the “electron-affinicgroup” may be altered. In some embodiments, the carbocyclic orheterocyclic moiety is aromatic and is preferably at the C7, C9, C10,C11, C12 or C20 position. In some preferred embodiments, the carbocyclicor heterocyclic moiety is (+) or(−)-2-(2,4,5,7-tetranitro-9-fluorenylideneaminooxy)-propionic acid(TAPA) or 2-(2,4,5,7-tetranitro-9-fluorenylideneaminooxy)-ethanoic acid.

Radiosensitizers by definition increase the sensitivity of cancerouscells to the toxic effects of ionizing radiation. While not wanting tobe limited to any particular theory, several mechanisms for the mode ofaction of radiosensitizers have been suggested. Hypoxic cellradiosensitizers (e.g., 2-nitroimidazole compounds, and benzotriazinedioxide compounds) promote reoxygenation of hypoxic tissue and/orcatalyze generation of damaging oxygen radicals. Nonhypoxic cellradiosensitizers (e.g., halogenated pyrimidines) can be analogs of DNAbases and preferentially incorporate into the DNA of cancer cells andthereby promote the radiation ion-induced breaking of DNA moleculesand/or prevent the normal DNA repair mechanisms. Various other potentialmechanisms of action have been hypothesized for radiosensitizers in thetreatment of disease. A discussion of radiosensitizer agents is providedin Rowinsky-E K, Oncology-Huntingt., October 1999; 13(10 Suppl 5):61-70; Chen-A Y et al., Oncology-Huntingt. October 1999; 13 (10 Suppl5): 39-46; Choy-H, Oncology-Huntingt. October 1999; 13 (10 Suppl 5):23-38; and Herscher-L L et al, Oncology-Huntingt. October 1999; 13 (10Suppl 5): 11-22.

A method is also provided for killing tumor cells in a warm-bloodedanimal which includes the steps of administering to the warm-bloodedanimal a pharmaceutical composition as described above in an amounteffective to radiosensitize the tumor cells, followed by, after a timeinterval sufficient to enhance radiosensitization of the tumor cells,irradiating the tumor cells with a dose of radiation effective to killthe tumor cells.

After administration of the radiosensitizing composition to the tumorcells and the passage of a time interval sufficient to enhanceradiosensitization of the tumor cells, the tumor cells are irradiatedwith a dose of radiation effective to destroy the tumor cells.Generally, the patient will receive a total radiation dosage of about 60to 76 Gy over seven to eight weeks, each individual radiation dose to begiven within approximately 1 to 4 hours after administration of theradiosensitizer. Such sequences of radiosensitization treatments andirradiation are repeated as needed to abate and, optimally, reduce oreliminate, the spread of the malignancy.

Another aspect of the invention provides methods of sensitizing tumorcells to radiation, said method comprising: a) administering to a humanor animal subject in need thereof a compound or a pharmaceuticallyacceptable salt thereof having formula (I), below, and b) exposing thesubject to a unit dose of ionizing radiation. In other aspect, thisinvention provides a method where steps a) and b) are applied to atreatment schedule effective to produce a synergistic anti-neoplasticeffect.

-   -   wherein W is alkyl-C(O)—, or R¹Y-L-C(O)—, provided that when W        is alkyl-C(O)—, at least one of R², R³, R⁴, R⁵, or R⁶ is nitro;    -   L is a bond or linear alkylene (1-8) group, optionally        substituted with lower alkyl or substituted lower alkyl, wherein        one or two methylene (—CH₂—) units of the linear alkylene group        is optionally replaced with O, S or NH;    -   Y is ═NO—, —N(H)O—, ═N—, —NR—, O, S, or a bond;    -   R is H, alkyl, or substituted alkyl;    -   R¹ is optionally substituted carbocyclic, heterocyclic, or fused        2-, 3- or 4-ring heterocyclic;    -   R² is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y, R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower        alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, tri lower alkylsilyl, lower alkylcarbonyloxy,        lower alkoxycarbonyloxy, sugar, phosphosugar, O-quinone,        substituted lower alkyl aminomethyl, lower alkylcarbonylamino,        lower alkylcarbonyloxy methyl, optionally substituted lower        alkylcarbonyloxy methyl, substituted vinyl,        1-hydroxy-2-nitroethyl, alkoxycarbonylethyl, aminocarbonyl,        alkylcarbonyl, benzoylmethyl, benzylcarbonyloxymethyl, lower        alkyliminomethyl or lower alkoxymethyl;    -   R³ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, CH₂NR⁷R⁸ (where each of R⁷ and R⁸ is        independently H, alkyl of 1-6 carbons, optionally substituted        phenyl, hydroxy lower alkyl, amino lower alkyl, or mono- or        dialkylamino lower alkyl, or R⁷ and R⁸ taken together with —N—        represent a cyclic amino-), CH₂R⁹ (where R⁹ is lower alkoxy,        cyano, amino lower alkoxy, mono- or di-lower alkylamino lower        alkoxy, lower alkylthio, amino lower alkylthio, or mono- or        di-lower alkylamino lower alkylthio), NR¹⁰R¹¹ (where each of R¹⁰        and R¹¹ is independently hydrogen, lower alkyl, phenyl, hydroxy        lower alkyl, or amino lower alkyl, or R¹⁰ and R¹¹ taken together        with —N— represent a cyclic amino), trialkylsilyl, dialkylamino        alkyl, lower alkylcarbonyloxy, lower alkoxycarbonyloxy, sugar,        phosphosugar, O-quinone, substituted lower alkyl aminomethyl, or        lower alkylcarbonylamino or R³ together with R⁴ is furan,        dihydrofuran or 1,4-oxazine-2-one; and    -   R⁴ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, amino lower alkyl,        halogenated lower alkyl, halogenated lower alkoxy,        hydroxycarbonyl, formyl, lower alkoxycarbonyl, carbamoyloxy,        lower alkylcarbonyloxy, lower alkoxycarbonyloxy, sugar,        phosphosugar, O-quinone, substituted lower alkyl aminomethyl, or        lower alkylcarbonylamino, or R⁴ together with R³ is furan,        dihydrofuran or 1,4-oxazine-2-one, or R⁴ together with R⁵ is        methylenedioxy;    -   R⁵ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, trialkylsilyl, halogenated        lower alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl,        lower alkoxycarbonyl, lower alkylcarbonyloxy, lower        alkoxycarbonyloxy, sugar, phosphosugar, O-quinone, substituted        lower alkyl aminomethyl, or lower alkylcarbonylamino, or R⁵        together with R⁴ is methylenedioxy;    -   R⁶ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, lower alkylcarbonyloxy, lower alkoxycarbonyloxy,        sugar, phosphosugar, O-quinone, substituted lower alkyl        aminomethyl, or lower alkylcarbonylamino; and    -   R^(Q) is optionally substituted carbocyclic, heterocyclic, or        fused 2-, 3- or 4-ring heterocyclic.

In some embodiments, W is R¹Y-L-C(O)—.

R¹ groups that may be incorporated into the active camptothecinderivative as described by Formula (I) include phenyl optionallysubstituted with from one to five substituents independently selectedfrom the group consisting of halo, lower alkyl, lower alkoxy, hydroxy,cyano, nitro, amino, halogenated lower alkyl, halogenated lower alkoxy,formyl, lower alkyl carbonyl, hydroxycarbonyl, lower alkylcarbonyloxy,benzyloxy, optionally substituted piperazino, lower alkoxycarbonyl, andlower alkylcarbonylamino; a fused, 2-, 3-, or 4-ring heterocyclic systemoptionally substituted with one to five substituents independentlyselected from the group consisting of halo, lower alkyl, lower alkoxy,hydroxy, cyano, nitro, amino, halogenated lower alkyl, halogenated loweralkoxy, hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyloxy,and lower alkylcarbonylamino; 1- or 2-naphthyl optionally substitutedwith from one to four substituents independently selected from the groupconsisting of halo, lower alkyl, lower alkoxy, hydroxy, cyano, nitro,amino, halogenated lower alkyl, halogenated lower alkoxy,hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyloxy, and loweralkylcarbonylamino; or a 5 or 6 membered heterocyclic ring containingone or two nitrogen atoms, which ring is optionally substituted with oneor two substituents selected from the group consisting of halo, loweralkyl, lower alkoxy, hydroxy, cyano, nitro, amino, halogenated loweralkyl, halogenated lower alkoxy, hydroxycarbonyl, lower alkoxycarbonyl,lower alkylcarbonyloxy, and lower alkylcarbonylamino. In a preferredembodiment, R¹ is substituted with at least one carbonyl, amido,trifluoromethyl, halogen, nitro, nitroso, sulfonyl, sulfinyl,phosphoryl, or oxo group. In other embodiments, R¹ is selected from thegroup consisting of O-quinone, semiquinone, fluorene, imidazole,triazole, pyridine, benzamide, nicotinamide, benzotriazine oxide, furan,thiophene, oxazole, or thiazole, where each of the aforementioned groupsmay be substituted or unsubstituted. In other embodiments, R¹ isaromatic.

Preferably at least one of R¹, R², R³, R⁴, R⁵, or R⁶ comprises anelectron-affinic moiety, wherein the electron-affinic moiety is a (i)nitro; (ii) carbocyclic or heterocyclic aromatic moiety possessing oneor more carbonyl, trifluoromethyl, halogen, nitro, sulfonyl, sulfinyl,phosphoryl, oxide or cyano groups; (iii) heterocyclic aromatic moietycontaining two or more heteroatoms; (iv) metal complex; or (v)organo-metallic group in which the metal is covalently bonded to carbon.

Carbocyclic or heterocyclic aromatic electron-affinic moieties containone to three rings with a total of 5 to 15 ring atoms. The heteroatomsare selected from the group consisting of N, S, O and P. Preferably, thecarbocyclic or heterocyclic aromatic electron-affinic moieties containone to two rings with one ring being presently most preferred.Representative carbocyclic aromatic electron-affinic moieties includephenyl and naphthyl groups containing one or more nitro, halogen,carbonyl or sulfonyl substituents, with nitro-substituted phenyl being apreferred carbocyclic aromatic electron-affinic moiety. Representativeheterocyclic aromatic electron-affinic moieties include imidazoles,triazoles, pyridines, benzamides, nicotinamides, benzotriazine oxides,furans, thiophenes, oxazoles and thiozoles possessing one or morecarbonyl, trifluoromethyl, halogen, nitro, sulfonyl, sulfinyl,phosphoryl, oxide or cyano groups, and preferably at least one nitrogroup.

Metal complex electron-affinic moieties preferably comprise Pt²⁺, Co³⁺,Fe²⁺, Fe³⁺, Pd²⁺, Cu²⁺, Ti⁴⁺, or Zr⁴⁺ as the metal and generally fallinto two subgroups: (a) metal complexes of the carbocyclic andheterocyclic aromatic electron-affinic moieties discussed above, and (b)metal complexes of bidentate ligands comprising nitrogen, carbon orsulfur. In general, metal complexes of bidentate ligands correspond tothe formula —BM^(L)X_(K) wherein B is a bidentate ligand containingnitrogen, carbon or sulfur, ML is a metal, X is an anionic ligand suchas Cl⁻ or ⁻OAc, and k is 1-4.

Organometallic electron-affinic moieties are aliphatic or aromaticmercury radicals. The preparation and use of radiosensitizing agentsincorporating mercury containing entities is described in Shenoy et al.,Cancer Investigation, 10(6):533-551 (1992) and Bruce et al., RadiationRes., 24:473-481 (1965).

Electron-affinic moieties that are particularly suitable for inclusionin the compound of Formula (I) include O-quinone, semiquinone, fluorene,imidazole, triazole, pyridine, benzamide, nicotinamide, benzotriazineoxide, furan, thiophene, oxazole, and thiazole, where each of theaforementioned groups may be substituted or unsubstituted. In apreferred embodiment, R¹ is selected from this group.

In a particularly preferred embodiment, the method of sensitizing tumorcells to radiation is using a camptothecin-based compound selected fromthe group consisting of:

In other embodiments, the electron-affinic moiety includes an R¹ that isa 2-nitroimidazol-1-yl or 3-nitro-1,2,4-triazol-1-yl group having thefollowing structure

wherein R²⁰ is halo, alkyl, or substituted alkyl.

The electron-affinic moieties may be directly attached to one of thecarbons at the C5, C7, C9, C10, C11, C12 or C20 position of camptothecinor indirectly attached via a linker. While the linker, L, may be anyalkylene group of 1 to 8 carbons, optionally interrupted by one or moreoxygen, sulfur or nitrogen atoms, a preferred linker is (CH₂)_(m) or-(T)_(n)-X—, wherein X is O, S, —NR—, or a bond; T is independentlyCRR′; m is an integer from 0 to 3; n is an integer from 1 to 3, and eachof R and R′ is independently selected from hydrogen, lower alkyl, andsubstituted lower alkyl.

In a particularly preferred embodiment, WO—, comprised in thesubstitution at the −20 position of the camptothecin derivative, isselected from the group consisting of

Present invention is further directed to a process for radiosensitizingtumor cells. The process comprises administering a radiosensitizingamount of the pharmaceutical composition described above to the tumorcells. Related thereto, a method is also provided for killing tumorcells in a warm-blooded animal which includes the steps of administeringto the warm-blooded animal a pharmaceutical composition as describedabove in an amount effective to radiosensitize the tumor cells, followedby, after a time interval sufficient to enhance radiosensitization ofthe tumor cells, irradiating the tumor cells with a dose of radiationeffective to kill the tumor cells.

As used herein, a “therapeutically effective amount” of CPT derivativesof the present invention is intended to mean that amount of the compoundfor inhibiting or retarding the growth of a malignant cell, or in thecase of a subject having a malignant tumor, the rate of tumor growth isdecreased, the volume of such tumor is reduced, or the tumor iseliminated entirely.

One aspect of this invention is a method for treating a mammal sufferingfrom a neoplasm by administering a camptothecin-based compound to themammal and directing ionizing radiation to the neoplasm. The compoundsuseful in this aspect of the invention are set forth in U.S. Pat. Nos.6,350,756 and 6,403,603, including any reissues thereof, both of whichare incorporated herein by reference in their entirety. The preferencesexpressed in the specification and claims of those patents are thepreferences of this aspect of the invention.

In general, the compounds of U.S. Pat. No. 6,350,756 are set forth asfollows:

wherein R is R¹—O— (CH₂)_(m)—, m is an integer of 1-10 and R¹ is

-   -   phenyl optionally substituted with from one to five substituents        independently selected from the group consisting of halo, lower        alkyl, lower alkoxy, hydroxy, cyano, nitro, amino, halogenated        lower alkyl, halogenated lower alkoxy, formyl, lower alkyl        carbonyl, hydroxycarbonyl, lower alkylcarbonyloxy, benzyloxy,        optionally substituted piperazino, lower alkoxycarbonyl, and        lower alkylcarbonylamino;    -   a fused, 2-, 3-, or 4-ring heterocyclic system optionally        substituted with one to five substituents independently selected        from the group consisting of halo, lower alkyl, lower alkoxy,        hydroxy, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, lower alkoxycarbonyl,        lower alkylcarbonyloxy, and lower alkylcarbonylamino;    -   1- or 2-naphthyl optionally substituted with from one to four        substituents independently selected from the group consisting of        halo, lower alkyl, lower alkoxy, hydroxy, cyano, nitro, amino,        halogenated lower alkyl, halogenated lower alkoxy,        hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyloxy,        and lower alkylcarbonylamino;    -   a 5 or 6 membered heterocyclic ring containing one or two        nitrogen atoms, which ring is optionally substituted with one or        two substituents selected from the group consisting of halo,        lower alkyl, lower alkoxy, hydroxy, cyano, nitro, amino,        halogenated lower alkyl, halogenated lower alkoxy,        hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyloxy,        and lower alkylcarbonylamino;    -   R² is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy, RC(O)O        (R is defined hereinbefore), cyano, nitro, amino, halogenated        lower alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl,        lower alkoxycarbonyl, tri lower alkylsilyl, lower        alkylcarbonyloxy, lower alkylcarbonylamino, lower        alkylcarbonyloxy methyl, substituted vinyl,        1-hydroxy-2-nitroethyl, alkoxycarbonylethyl, aminocarbonyl,        alkylcarbonyl, alkylcarbonyloxymethyl, benzoylmethyl,        benzylcarbonyloxymethyl, or lower alkoxymethyl;    -   R³ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy, RC(O)O        (R is defined hereinbefore) cyano, nitro, amino, halogenated        lower alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl,        lower alkoxycarbonyl, CH₂ NR⁷R⁸ (where each of R⁷ and R⁸ is        independently H—, alkyl of 1-6 carbons, optionally substituted        phenyl, hydroxy lower alkyl, amino lower alkyl, or mono- or        dialkylamino lower alkyl, or R⁷ and R⁸ taken together with —N—        represent a cyclic amino-), CH₂R⁹ (where R⁸ is lower alkoxy, CN,        amino lower alkoxy, mono- or di-lower alkylamino lower alkoxy,        lower alkylthio, amino lower alkylthio, or mono- or di-lower        alkylamino lower alkylthio), or NR¹⁰R¹¹ (where each of R¹⁰ and        R¹¹ is independently hydrogen, lower alkyl, phenyl, hydroxy        lower alkyl, or amino lower alkyl, or R¹⁰ and R¹¹ taken together        with —N— represent a cyclic amino), dialkylamino alkyl, lower        alkylcarbonyloxy lower alkylcarbonylamino; and    -   R⁴ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy, RC(O)O        (R is defined hereinbefore) cyano, nitro, amino, amino lower        alkyl, halogenated lower alkyl, halogenated lower alkoxy,        hydroxycarbonyl, formyl, lower alkoxycarbonyl, carbamoyloxy,        lower alkylcarbonyloxy, or lower alkylcarbonylamino, or R⁴        together with R⁵ is methylenedioxy;    -   R⁵ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy, RC(O)O        (R is defined hereinbefore) cyano, nitro, amino, halogenated        lower alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl,        lower alkoxycarbonyl, lower alkylcarbonyloxy, or lower        alkylcarbonylamino; and    -   R⁶ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy, RC(O)O        (R is defined hereinbefore) cyano, nitro, amino, halogenated        lower alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl,        lower alkoxycarbonyl, lower alkylcarbonyloxy, or lower        alkylcarbonylamino.

The compounds of U.S. Pat. No. 6,403,604 are set forth as follows:

wherein R is R^(a)R^(b)N— (CH₂)_(m), m is 2,

-   -   R^(a)R^(b) together with N form (a) a 5-, 6-, or 7-membered        cyclic amine having no more than one additional nitrogen,        oxygen, or sulfur atom in the ring, which ring is fused to        another, carbocyclic ring or rings which resulting fused ring        system is optionally substituted with up to two substituents        chosen from lower alkyl, lower cycloalkyl, hydroxy lower alkyl,        phenyl, substituted phenyl (substituted with one to five        substituents independently selected from the group consisting of        halo, lower alkyl, lower alkoxy, hydroxy, cyano, nitro, amino,        halogenated lower alkyl, halogenated lower alkoxy, carbonyl,        hydroxycarbonyl, lower alkylcarbonyloxy, benzyloxy, optionally        substituted piperidino, lower alkoxycarbonyl, and lower        alkylcarbonylamino), benzyl, substituted benzyl (substituted        with one to five substituents independently selected from the        group consisting of halo, lower alkyl, lower alkoxy, hydroxy,        cyano, nitro, amino, halogenated lower alkyl, halogenated lower        alkoxy, carbonyl, hydroxycarbonyl, lower alkylcarbonyloxy,        benzyloxy, optionally substituted piperidino, lower        alkoxycarbonyl, and lower alkylcarbonylamino),        aminocarbonylmethyl, lower alkylaminocarbonylmethyl, amino,        mono- or di-lower alkyl amino, cyclic amino, or a 5- or        6-membered heterocyclic ring optionally substituted with one or        two substituents selected from the group consisting of halo,        lower alkyl, lower alkoxy, hydroxy, cyano, nitro, amino,        halogenated lower alkyl, halogenated lower alkoxy,        hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyloxy,        and lower alkylcarbonylamino or (b) a 5- or 6-membered cyclic        imide ring;    -   R² is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy, RC(O)O        (R is defined hereinbefore), cyano, nitro, amino, halogenated        lower alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl,        lower alkoxycarbonyl, tri lower alkylsilyl, lower        alkylcarbonyloxy, lower alkylcarbonylamino, lower        alkylcarbonyloxymethyl, substituted vinyl,        1-hydroxy-2-nitroethyl, alkoxycarbonylethyl, aminocarbonyl,        alkylcarbonyl, alkylcarbonyloxymethyl, benzoylmethyl,        benzylcarbonyloxymethyl, or lower alkoxymethyl,    -   R³ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy, RC(O)O        (R is defined hereinbefore) cyano, nitro, amino, halogenated        lower alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl,        lower alkoxycarbonyl, CH₂ NR⁷R⁸ (where each of R⁷ and R⁸ is        independently H—, alkyl of 1-6 carbons, optionally substituted        phenyl, hydroxy lower alkyl, amino lower alkyl, or mono- or        dialkylamino lower alkyl, or R⁷ and R⁸ taken together with —N—        represent a saturated 5-, 6-, or 7 membered cyclic amine ring        having no more than one additional nitrogen, oxygen or sulfur        atom that is optionally fused to another carbocyclic ring or        rings), CH₂R⁹ (where R⁹ is lower alkoxy, CN, amino lower alkoxy,        mono- or di-lower alkylamino lower alkoxy, lower alkylthio,        amino lower alkylthio, or mono- or di-lower alkylamino lower        alkylthio), or NR¹⁰R¹¹ (where each of R¹⁰ and R¹¹ is        independently hydrogen, lower alkyl, phenyl, hydroxy lower        alkyl, or amino lower alkyl, or R¹⁰ and R¹¹ taken together with        —N— represent a saturated 5-, 6, or 7 membered cyclic amine ring        having no more than one additional nitrogen, oxygen or sulfur        atom that is optionally fused to another carbocyclic ring or        rings), dialkylamino alkyl, lower alkylcarbonyloxy, or lower        alkylcarbonylamino; and    -   R⁴ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy, RC(O)O        (R is defined hereinbefore) cyano, nitro, amino, amino lower        alkyl, halogenated lower alkyl, halogenated lower alkoxy,        hydroxycarbonyl, formyl, lower alkoxycarbonyl, carbamoyloxy,        lower alkylcarbonyloxy, or lower alkylcarbonylamino, or R⁴        together with R⁵ is methylenedioxy;    -   R⁵ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy, RC(O)O        (R is defined hereinbefore) cyano, nitro, amino, halogenated        lower alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl,        lower alkoxycarbonyl, lower alkylcarbonyloxy, or lower        alkylcarbonylamino; and    -   R⁶ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy, RC(O)O        (R is defined hereinbefore) cyano, nitro, amino, halogenated        lower alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl,        lower alkoxycarbonyl, lower alkylcarbonyloxy, or lower        alkylcarbonylamino.

Another aspect of the invention is a method of enhancing thechemoradiosensitization efficacy of a camptothecin-based compound bychemically positioning an electron-affinic moiety at the C5, C7, C9,C10, C11, C12 or C20 position of the camptothecin molecule. Thechemoradiosensitization characteristic is the capability of a compound,when administered to a subject having a neoplasm, to be absorbed by thesubject and directed to the neoplasm to make the neoplasm moresusceptible to radiation therapy than it would be without theadministration of the compound to the subject. These enhanced compoundsthen are useful for treating a subject suffering from a neoplasm byadministering such a compound to the subject and directing radiation tothe subject's neoplasm. Preferably, the electron-affinic group is anitro-substituted carbocyclic or heterocyclic aromatic group.

4. Compounds of the Invention

Novel compounds that are particularly valuable in all aspects of theinvention are those represented by formula (II) as follows:

wherein

-   -   X is a O, S, —NR—, or a bond;    -   Y is ═NO—, —N(H)O—, ═N—, —NR—, O, S, or a covalent bond;    -   T is independently CRR′;    -   each of R and R′ is independently selected from hydrogen,        alkyl₁₋₄, and substituted alkyl₁₄;    -   n is an integer from 0 to 8;    -   R¹ is optionally substituted heterocyclic, aryl, or heteroaryl;        -   provided that when X is a bond or CH₂ and n is 1, 2, or 3,            then Y, when bound to R¹, is not oxygen; and        -   provided that when X is a bond or CH₂, n is 1, 2, or 3; and            R¹ is heterocyclic containing at least one nitrogen atom,            then Y is not bound directly to said nitrogen atom;    -   R² is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, tri lower alkylsilyl, lower alkylcarbonyloxy,        lower alkoxycarbonyloxy, sugar, phosphosugar, O-quinone,        substituted lower alkyl aminomethyl, lower alkylcarbonylamino,        lower alkylcarbonyloxy methyl, optionally substituted lower        alkylcarbonyloxy methyl, substituted vinyl,        1-hydroxy-2-nitroethyl, alkoxycarbonylethyl, aminocarbonyl,        alkylcarbonyl, alkylcarbonyloxymethyl, benzoylmethyl,        benzylcarbonyloxymethyl, lower alkyliminomethyl or lower        alkoxymethyl;    -   R³ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, CH₂NR⁷R⁸ (where each of R⁷ and R⁸ is        independently H, alkyl of 1-6 carbons, optionally substituted        phenyl, hydroxy lower alkyl, amino lower alkyl, or mono- or        dialkylamino lower alkyl, or R⁷ and R⁸ taken together with —N—        represent a cyclic amino-), CH₂R⁹ (where R⁹ is lower alkoxy, CN,        amino lower alkoxy, mono- or di-lower alkylamino lower alkoxy,        lower alkylthio, amino lower alkylthio, or mono- or di-lower        alkylamino lower alkylthio), NR¹⁰R¹¹ (where each of R¹⁰ and R¹¹        is independently hydrogen, lower alkyl, phenyl, hydroxy lower        alkyl, or amino lower alkyl, or R¹⁰ and R¹¹ taken together with        —N— represent a cyclic amino), trialkylsilyl, dialkylamino        alkyl, lower alkylcarbonyloxy, lower alkoxycarbonyloxy, sugar,        phosphosugar, O-quinone, substituted lower alkyl aminomethyl, or        lower alkylcarbonylamino or R³ together with R⁴ is furan,        dihydrofuran or 1,4-oxazine-2-one;    -   R⁴ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, amino lower alkyl,        halogenated lower alkyl, halogenated lower alkoxy,        hydroxycarbonyl, formyl, lower alkoxycarbonyl, carbamoyloxy,        lower alkylcarbonyloxy, lower alkoxycarbonyloxy, sugar,        phosphosugar, O-quinone, substituted lower alkyl aminomethyl, or        lower alkylcarbonylamino, or R⁴ together with R³ is furan,        dihydrofuran or 1,4-oxazine-2-one, or R⁴ together with R⁵ is        methylenedioxy;    -   R⁵ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, lower alkylcarbonyloxy, lower alkoxycarbonyloxy,        sugar, phosphosugar, O-quinone, substituted lower alkyl        aminomethyl, or lower alkylcarbonylamino;    -   R⁶ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, trialkylsilyl, halogenated        lower alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl,        lower alkoxycarbonyl, lower alkylcarbonyloxy, lower        alkoxycarbonyloxy, sugar, phosphosugar, O-quinone, substituted        lower alkyl aminomethyl, or lower alkylcarbonylamino;    -   L is a linker containing a linker chain having 1 to 10 atoms        independently selected from the group consisting of N, C, or O;        and    -   R^(Q) is an optionally substituted heterocyclic, aryl, or        heteroaryl group, or R¹Y together form a NR^(a)R^(b) group,        where R^(a), R^(b), and the nitrogen to which they are attached        form a cyclic amine or imide ring.

In one embodiment, one of the R², R⁴, or R⁵ is selected from the groupconsisting of (tris(hydroxymethyl)methylamino)methyl,(bis(hydroxymethyl)methylamino)methyl, and (2-hydroxyethylamino)methyl.In a preferred embodiment, R² is selected from the group consisting of(tris(hydroxymethyl)methylamino)methyl,(bis(hydroxymethyl)methylamino)methyl, and (2-hydroxyethylamino)methyl.

In another embodiment, R² is selected from the group consisting of(tris(hydroxymethyl)methylamino)methyl,(bis(hydroxymethyl)methylamino)methyl, and (2-hydroxyethylamino)methyl;R³ is hydrogen, dimethylamino, amino, or nitro; R⁴ is hydrogen, hydroxy,or 4-(1-piperidino)-1-piperidinocarbonyloxy; or R⁴ together with R⁵ ismethylenedioxy; R⁵ is hydrogen; or R⁵ together with R⁴ ismethylenedioxy; and R⁶ is hydrogen.

In another embodiment, R² is selected from the group consisting of(tris(hydroxymethyl)methylamino)methyl,(bis(hydroxymethyl)methylamino)methyl, and (2-hydroxyethylamino)methyl;R³ is hydrogen; R⁴ together with R⁵ is methylenedioxy and R⁶ ishydrogen.

In yet another embodiment, R² is selected from the group consisting of(tris(hydroxymethyl)methylamino)methyl,(bis(hydroxymethyl)methylamino)methyl, and (2-hydroxyethylamino)methyland each of R³, R⁴, R⁵, and R⁶ is hydrogen.

In a preferred embodiment R¹ is aromatic. In a preferred embodiment X isa covalent bond. Additionally it is preferred that Y is ═NO— or —N(H)O—and even more preferably that n is 1 and each of R and R′ isindependently methyl or hydrogen. In a further preferred embodiment, R¹is a substituted or unsubstituted carbocyclic, preferably having 1 to 4aromatic rings. The substituted or unsubstituted carbocyclic may be9-fluorenyl, preferably substituted with at least one nitro group. Inone embodiment of the compound, R¹ is

In a preferred embodiment, the camptothecin-based compound is selectedfrom the group consisting of

In another preferred embodiment, the compound of Formula (II) includesan R¹ or R^(Q) that is

wherein R²⁰ is halo, alky, or substituted alkyl.

In yet another preferred embodiment of Formula (II),R¹Y-(T)_(n)-X—C(O)O— is

Certain camptothecin derivatives are particularly desirable, forexample, a compound of the formula (II), wherein

-   -   R² is hydrogen;    -   R³ is CH₂NR⁷R⁸ (where each of R⁷ and R⁸ is independently H,        alkyl of 1-6 carbons, optionally substituted phenyl, hydroxy        lower alkyl, amino lower alkyl, or mono- or dialkylamino lower        alkyl, or R⁷ and R⁸ taken together with —N— represent a cyclic        amino-), NR¹⁰R¹¹ (where each of R¹⁰ and R¹¹ is independently        hydrogen, lower alkyl, phenyl, hydroxy lower alkyl, or amino        lower alkyl, or R¹⁰ and R¹¹ taken together with —N— represent a        cyclic amino), or dialkylamino alkyl;    -   R⁴ is lower alkoxy, hydroxy, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, carbamoyloxy, lower alkylcarbonyloxy, lower        alkoxycarbonyloxy, sugar, phosphosugar, or R⁴ together with R⁵        is methylenedioxy;    -   R⁵ is hydrogen or together with R⁴ is methylenedioxy; and    -   R⁶ is hydrogen.

More preferably, R³ is CH₂NR⁷R⁸ (where each of R⁷ and R⁸ is loweralkyl), R⁴ is hydroxy, alkoxy, or alkylcarbonyloxy, and R⁵ is hydrogen.In a particularly preferred embodiment of this compound, R³ isCH₂N(CH₃)₂ and/or R⁴ is hydroxy.

Similarly, a preferred compound of Formula (II) has the followingfeatures:

-   -   R² is hydrogen, lower alkyl or halogenated lower alkyl;    -   R³ is hydrogen or lower alkyl;    -   R⁴ is lower alkoxy, hydroxy, halogenated lower alkoxy,        hydroxycarbonyl, carbamoyloxy, lower alkylcarbonyloxy, lower        alkoxycarbonyloxy, sugar, phosphosugar, or R⁴ together with R⁵        is methylenedioxy;    -   R⁵ is hydrogen or together with R⁴ is methylenedioxy; and    -   R⁶ is hydrogen.

Preferably, R³ is hydrogen, R⁴ is carbamoyloxy, and R⁵ is hydrogen. Evenmore preferably, R² is lower alkyl, especially ethyl, and R⁴ is4-(1-piperidino)-1-piperidinocarbonyloxy.

In other embodiments of invention, R² is hydrogen and R⁴ is4-(1-piperidino)-1-piperidinocarbonyloxy.

In other embodiments of invention, R² is hydrogen, R³ is hydrogen and R⁴is tert-butoxycarbonyloxy.

Yet another preferred compound of the invention is has Formula (II),wherein

-   -   R² is lower alkyl;    -   R³ is hydrogen;    -   R⁴ is hydroxy, lower alkoxy, halogenated lower alkoxy,        hydroxycarbonyl, formyl, lower alkoxycarbonyl, lower        alkoxycarbonyloxy, sugar, phosphosugar, or lower        alkylcarbonyloxy;    -   R⁵ is hydrogen; and    -   R⁶ is hydrogen.

Preferably, R² is ethyl and R⁴ is hydroxy.

Yet another preferred compound of the invention is of Formula (II) whereR², R⁴, R⁵ and R⁶ are hydrogen and R³ is amino or nitro. An alternativecompound of Formula (II) has the following substituents:

-   -   R² is tri-lower alkylsilyl;    -   R³ is hydrogen;    -   R⁴ is hydroxy, lower alkoxy, halogenated lower alkoxy,        hydroxycarbonyl, formyl, lower alkoxycarbonyl, lower        alkoxycarbonyloxy, sugar, phosphosugar, carbamoyloxy or lower        alkylcarbonyloxy;    -   R⁵ is hydrogen; and    -   R⁶ is hydrogen.

Preferably, R² is t-butyldimethylsilyl and R⁴ is hydroxy.

While the linker, L, may be any alkylene group of 1 to 8 carbons,optionally interrupted by one or more oxygen, sulfur or nitrogen atoms,a preferred linker is (CH₂)_(m) or -(T)_(n)-X—, wherein X is O, S, —NR—,or a bond; T is independently CRR′; m is an integer from 0 to 3; n is aninteger from 1 to 3, and each of R and R′ is independently selected fromhydrogen, alkyl, and substituted alkyl.

In some embodiments, this invention also provides a compositioncomprising a compound of this invention together with a pharmaceuticallyacceptable excipient.

In some embodiments, this invention also provides a method for treatinga cancer disorder in a subject having a tumor which method comprisesadministering to the subject a composition a composition comprising acompound of this invention together with a pharmaceutically acceptableexcipient. The method further comprises exposing the tumor in thesubject to a unit dose of radiation.

In some embodiments, this invention also provides a method of treating aneoplasm comprising:

a) administering to the subject a compound or a pharmaceuticallyacceptable salt thereof having formula (I) and b) exposing said subjectto a unit dose of radiation.

-   -   wherein W is alkylC(O)—, or R¹Y-L-C(O)—, provided that when W is        alkylC(O)—, at least one of R², R³, R⁴, R⁵, or R⁶ is nitro;    -   L is a bond or linear alkylene (1-8) group, optionally        substituted with lower alkyl or substituted lower alkyl, wherein        one or two methylene (—CH₂—) units of the linear alkylene group        is optionally replaced with O, S or NH;    -   Y is ═NO—, —N(H)O—, ═N—, —NR—, O, S, or a bond;    -   R is H, alkyl, or substituted alkyl;    -   R¹ is optionally substituted carbocyclic, heterocyclic, or fused        2-, 3- or 4-ring heterocyclic;    -   R² is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y, R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower        alkyl, halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, lower alkoxycarbonyloxy, sugar, phosphosugar,        O-quinone, substituted lower alkyl aminomethyl, tri lower        alkylsilyl, lower alkylcarbonyloxy, lower alkylcarbonylamino,        lower alkylcarbonyloxy methyl, substituted vinyl,        1-hydroxy-2-nitroethyl, alkoxycarbonylethyl, aminocarbonyl,        alkylcarbonyl, alkylcarbonyloxymethyl, benzoylmethyl,        benzylcarbonyloxymethyl, or lower alkoxymethyl;    -   R³ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, lower alkoxycarbonyloxy, sugar, phosphosugar,        O-quinone, substituted lower alkyl aminomethyl, CH₂NR⁷R⁸ (where        each of R⁷ and R⁸ is independently H, alkyl of 1-6 carbons,        optionally substituted phenyl, hydroxy lower alkyl, amino lower        alkyl, or mono- or dialkylamino lower alkyl, or R⁷ and R⁸ taken        together with —N— represent a cyclic amino-), CH₂R⁹ (where R⁹ is        lower alkoxy, CN, amino lower alkoxy, mono- or di-lower        alkylamino lower alkoxy, lower alkylthio, amino lower alkylthio,        or mono- or di-lower alkylamino lower alkylthio), NR¹⁰R¹¹ (where        each of R¹⁰ and R¹¹ is independently hydrogen, lower alkyl,        phenyl, hydroxy lower alkyl, or amino lower alkyl, or R¹⁰ and        R¹¹ taken together with —-N— represent a cyclic amino),        dialkylamino alkyl, lower alkylcarbonyloxy, or lower        alkylcarbonylamino; and    -   R⁴ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, amino lower alkyl,        halogenated lower alkyl, halogenated lower alkoxy,        hydroxycarbonyl, formyl, lower alkoxycarbonyl, lower        alkoxycarbonyloxy, sugar, phosphosugar, O-quinone, substituted        lower alkyl aminomethyl, carbamoyloxy, lower alkylcarbonyloxy,        or lower alkylcarbonylamino, or R⁴ together with R⁵ is        methylenedioxy;    -   R⁵ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, lower alkylcarbonyloxy, lower alkoxycarbonyloxy,        sugar, phosphosugar, O-quinone, substituted lower alkyl        aminomethyl, or lower alkylcarbonylamino;    -   R⁶ is hydrogen, halo, lower alkyl, lower alkoxy, hydroxy,        R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,        halogenated lower alkoxy, hydroxycarbonyl, formyl, lower        alkoxycarbonyl, lower alkylcarbonyloxy, lower alkoxycarbonyloxy,        sugar, phosphosugar, O-quinone, substituted lower alkyl        aminomethyl, or lower alkylcarbonylamino; and    -   R^(Q) is optionally substituted carbocyclic, heterocyclic, or        fused 2-, 3- or 4-ring heterocyclic; and

5. Synthesis of Compounds of the Invention

The compounds of the invention are prepared by reacting a knowncamptothecin-based compound having a free hydroxyl or an amine groupwith an appropriate electron-affinic moiety. Many camptothecin-basedcompounds are generally available in the art and would be known to oneof ordinary skill in the art.

As Camptothecin (CPT) exhibits antineoplastic activity, severalsynthetic and semisynthetic analogs of CPT have been reported in theliterature. A number of attempts have been made not only to reduce itstoxicity while maintaining antitumor activity by converting CPT into itsderivatives but also to make it more water soluble by chemicalmodifications. Scientists continue to develop analogs in order toimprove the pharmacokinetics, drug resistance, clinical efficacy, andtoxicity profile of CPT. Based on the knowledge about total synthesisand semi-synthesis of CPT analogs, there are numerous possible ways ofattaching electron-affinic groups at various positions on the CPTmolecule. The radiosensitizing compounds of this invention can beprepared by linking the electron-affinic group to any of the C5, C7, C9,C₁₀, C11, C12 or C20 carbons of CPT using a variety of methods. Thefollowing Schemes 1 to 7 demonstrate a few representative examples ofthe same.

C20 Analogs

Compounds having electron-affinic groups at C20 may be prepared byreacting CPT or a CPT analog with a carboxylic acid of the formulaR¹Y-(T)_(n)-X—COOH wherein R¹, Y, (T)_(n), and X are as defined herein.

For example, an electron-affinic group, such as tetranitrofluorene, canbe attached to the 20 position via an ester linkage by treating a CPTanalog with 1,3-dicyclohexylcarbodiimide (DCC) and(+)-2-(2,4,5,7-tetranitro-9-fluorenylideneaminooxy)-propionic acid(TAPA) (commercially available from Wiley) in dry methylene chloride atroom temperature to provide the ester 1.1 as shown below (Scheme 1).Optionally the imine double bond in ester 1.1 can be reacted with areducing agent such as sodium borohydride (NaBH₄) to give the amine 1.2.

The above reaction can be carried out with a suitable CPT analog that issubstituted at any of the 5, 7, 9, 10, 11 or 12 positions. The CPTanalog may be substituted with substituents known in the art or that canbe prepared by one of skill in the art. Representative articles thatteach how to make such analogs or where such analogs may be procured arefound in the following journals.

-   1. J. Med. Chem. 1998, 41, 31-37-   2. J. Med. Chem. 2000, 43, 3970-3980-   3. J. Med. Chem. 1993, 36, 2689-2700-   4. J. Med Chem. 1991, 34, 98-107-   5. J. Med. Chem. 2000, 43, 3963-3969-   6. Chem. Pharm. Bull. 1991, 39(10), 2574-2580-   7. Chem. Pharm. Bull. 1991, 39(6), 1446-1454-   8. Antimicrobial Agents and Chemotherapy, December 1999, 2862-2868-   9. European Journal of Cancer 1998, 34(10), 1500-1503-   10. Cancer Research, Feb. 15, 1995, 55, 753-760-   11. Anti-Cancer Drug Design 1998, 13, 145-157-   12. Bioorg. Med. Chem. Lett. 1998, 8, 415-418-   13. Bioorg. Med. Chem. Lett. 2003, 11, 451.-   14. Biochem. Pharmacol. 2005, 70(8), 1125-1136-   15. Cancer Chemother. Pharmacol., Aug. 20, 2005, 1-10-   16. Bioorg. Med. Chem., Feb. 6, 2003, 11(3), 451-458.-   17. Cancer Chemother. Pharmacol., 2001, 48(1), 83-87-   18. Bioorg. Med. Chem. Lett. 2003, 13, 3739-3741-   19. Jpn. J. Cancer Res. 1995, 86, 776-782-   20. J. Chromatogr. B Analyt. Technol. Biomed. Life Sci. 2003, 784,    25-31-   21. Biomed Chromatogr. 2003, 17(6), 385-90-   22. Yao. Xue. Xue. Bao. 2005, 40(3), 241-247-   23. Bioorg. Med. Chem. Lett. 2005, 15(13), 3233-3236-   24. Bioorg. Med. Chem. 2004, 12(15), 4003-4008-   25. Expert Opin. Investig. Drugs 2004, 13(3), 269-284-   26. J. Med. Chem., Feb. 26, 2004, 47(5), 1280-1289-   27. Blood 2005, 105(9), 3714-3721-   28. J. Enzy. Inhib. Med. Chem. 2003, 18(2), 101-109-   29. Bioorg. Med. Chem. Lett. 2005, 15, 2003-2006-   30. Anticancer Drugs 2004, 15, 545-552-   31. Bioorg. Med. Chem. 2003, 11, 1851-1857-   32. Peptides 2005, 26, 1560-1566-   33. Bioorg. Med. Chem. Lett. 2004, 14, 4023-4026-   34. Bioorg. Med. Chem. 2004, 12, 3657-3662-   35. Cancer Research 2004, 64, 6679-6683

Suitable CPT analogs include the following, where the number inparenthesis following the name refers to the journal article listedabove:

-   (20S)-7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)-CPT    (AKA-irinotecan);-   (20S)-9-nitro CPT (1);-   (20S)-7-chloro-n-propyldimethylsilyl CPT (2);-   (20S)-10-hydroxy-7-chloro-n-propyldimethylsilyl CPT (2);-   (20S)-10-acetoxy-7-chloro-n-propyldimethylsilyl CPT (2);-   (20S)-7-tert-butyldimethylsilyl CPT (2);-   (20S)-10-hydroxy-7-tert-butyldimethylsilyl CPT (2);-   (20S)-10-acetoxy-7-tert-butyldimethylsilyl CPT (2);-   (20S)-9-hydroxy CPT (3);-   (20S)-9-amino CPT (3);-   (20S)-10-amino CPT (3);-   (20S)-9-amino-10-hydroxy CPT (3);-   (20S)-9-methylamino CPT;-   (20S)-9-chloro CPT (3);-   (20S)-9-fluoro CPT (3);-   (20S)-9-piperidino CPT;-   (20S)-9-dimethylaminomethyl-10-hydroxy CPT (3)-AKA topotecan);-   (20S)-9-morpholinomethyl CPT (4);-   (20S)-10-hydroxy CPT (3);-   (20S)-9,10-dichloro CPT (3);-   (20S)-10-bromo CPT (3);-   (20S)-10-chloro CPT (3);-   (20S)-10-methyl CPT (3);-   (20S)-10-fluoro CPT (3);-   (20S)-10-nitro CPT (3);-   (20S)-10,11-methylenedioxy CPT (3);-   (20S)-10-formyl CPT (3);-   (20S)-10-nonylcarbonyloxy CPT (12);-   (20S)-10-undecylcarbonyloxy CPT (12);-   (20S)-10-heptadecylcarbonyloxy CPT (12);-   (20S)-10-nonadecylcarbonyloxy CPT (12);-   (20S)-9-nitro-10,11-methylenedioxy CPT (3);-   (20S)-9-(4-methylpiperazinylmethyl)-10-hydroxy (CPT) (4);-   (20S)-9-[4-(1-piperidino)-1-piperidinomethyl]-10-hydroxy CPT (4);-   (20S)-9-methyl-10,11-methylenedioxy CPT;-   (20S)-9-chloro-10,11-methylenedioxy CPT (3);-   (20S)-9-cyano-10,11-methylenedioxy CPT;-   (20S)-9-acetoxy-10,11-methylenedioxy CPT;-   (20S)-9-acetylamino-10,11-methylenedioxy CPT;-   (20S)-9-aminomethyl-10-hydroxy CPT;-   (20S)-9-ethoxymethyl-10-hydroxy CPT (4);-   (20S)-9-methylaminomethyl-10-hydroxy CPT;-   (20S)-9-n-propylaminomethyl-10-hydroxy CPT (4);-   (20S)-9-dimethylaminomethyl-10-hydroxy CPT (4);-   (20S)-9-cyclohexylaminomethyl-10-hydroxy CPT (4);-   (20S)-9-(2-hydroxyethyl)aminomethyl-10-hydroxy CPT (4);-   (20S)-9-(trimethylammonio)methyl-10-hydroxy CPT, methanesulfonate    (4);-   (20S)-9-morpholinomethyl-10-hydroxy CPT (4);-   (20S)-5-(2-hydroxyethoxy) CPT-   (20S)-9-cyanomethyl-10-hydroxy CPT (4);-   (20S)-CPT-7-aldehyde (5);-   (20S)-10-methoxy CPT-7-aldehyde (5);-   (20S)-7-acetoxymethyl CPT (5);-   (20S)-7-acetoxymethyl-10-methyl CPT (5);-   (20S)-7-cyano-10-methoxy CPT (5);-   (20S)-7-cyano CPT (5);-   (20S)-7-formylethenyl CPT (5);-   (20S)-7-ethoxycarbonylethenyl CPT (5);-   (20S)-7-cyanoethenyl CPT (5);-   (20S)-7-(2,2-dicyanoethenyl) CPT (5);-   (20S)-7-(2-cyano-2-ethoxycarbonyl)ethenyl CPT (5);-   (20S)-7-ethoxycarbonylethyl CPT (5);-   (20S)-7-ethyl CPT (6);-   (20S)-7-n-propyl CPT (6);-   (20S)-7-acetoxymethyl CPT (6);-   (20S)-7-n-propylcarbonyloxymethyl CPT (6);-   (20S)-7-ethoxycarbonyl CPT (6);-   (20S)-7-ethyl-10-hydroxy CPT;-   (20S)-7-ethyl-10-acetyloxy CPT;-   (20S)-7-methyl-10-aminocarbonyloxy CPT;-   (20S)-7-n-propyl-10-piperidinocazbonyloxy CPT;-   (20S)-7-ethyl-10-(2-dimethylamino)ethyl CPT; and-   (20S)-7-ethyl-10-carbamoyloxy derivatives of CPT such as-   (20S)-7-ethyl-10-[4(1-piperidino)-piperidino carbonyloxy CPT (7);-   (20S)-7-ethyl-10-(1-piperazine)carbonyloxy CPT (7);-   (20S)-7-ethyl-10-(4-1-propylaminocarbonylmethylpiperazine)carbonyloxy    CPT (7);-   (20S)-7-ethyl-10-[4(1-pyrrolidinyl)piperazine]carbonyloxy CPT (7);-   (20S)-7-ethyl-10-[(4-(dimethylamino)-1-piperidino]carbonyloxy CPT    (7);-   (20S)-7-ethyl-10-[4-(di-n-propylamino)-1-piperidinol]carbonyloxy CPT    (7);-   (20S)-7-ethyl-10-[(4-(di-n-butylamino)-1-piperidino]carbonyloxy CPT    (7);-   (20S)-7-ethyl-10-[4-(1-pyrrolidino)-1-piperidino)]carbonyloxy CPT    (7);-   (20S)-7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy CPT (7);-   (20S)-7-ethyl-10-[N-methyl-N-2-(dimethylamino)ethylamino]carbonyloxy    CPT (7)-   (20S)-7-(tert-butyldimethylsilyl)CPT (13)-   (20S)-7-(tert-butoxyiminomethyl) CPT (Gimatecan) (14)-   (20S)-7-butyl-10,11-methylenedioxy CPT (15)-   (20S)-7-bromomethyl-10-hydroxy CPT (15)-   (20S)-7-butyl-10-amino CPT (15)-   (20S)-7-(tert-butyldimethylsilyl)-10-hydroxy CPT (16)-   (20S)-7-[(2-trimethylsilyl)ethyl)] CPT (Karentican) (17)-   (20S)-7-[(4-fluorophenoxy)acetyloxymethyl] CPT (18)-   (20S)-7-[(4-methoxyphenoxy)acetyloxymethyl] CPT (18)-   (20S)-7-[(4-cyano-3-fluorophenoxy)acetyloxymethyl] CPT (18)-   (20S)-7-[(3,4,5-trimethoxyphenyl)acetyloxymethyl] CPT (18)-   (20S)-10-[(4-cyano-3-fluorophenoxy)acetyloxy] CPT (18)-   (20S)-10-[(3,4,5-trimethoxyphenyl)acetyloxy] CPT (18)-   (20S)-7-(4-methylpiperazinomethylene)-10,11-ethylenedioxy CPT    (Exatecan) (19)-   (20S)-7-[2-(N-isopropylamino)ethyl] CPT (Belotecan) (20)-   (20S)-[5(RS)-(2-hydroxyethoxy)] CPT (21)-   (20S)-7-ethyl-9-allyl-10-hydroxy CPT (29)-   (20S)-7-ethyl-9-allyl-10-methoxy CPT (29)-   (20S)-7-ethyl-9-propyl-10-hydroxy CPT (29)    (20S)-7-ethyl-9-propyl-10-methoxy CPT-   (20S)-7,9-diethyl-10-hydroxy CPT (29)-   (20S)-7,9-diethyl-10-methoxy CPT (29)-   (20S)-10-(substituted quaternary ammonium salts) CPT (33)-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl CPT (35)-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl CPT (35)-   (20S)-7-(2-hydroxyethylamino)methyl CPT (35)-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10,11-methylenedioxy    CPT (35)-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10,11-methylenedioxy    CPT (35)-   (20S)-7-(2-hydroxyethylamino)methyl-10,11-methylenedioxy CPT (35)-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-amino CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-amino CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-amino CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-nitro CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-nitro CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-nitro CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10-hydroxy CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10-hydroxy CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10-hydroxy CPT; and the like.

It will be recognized by one of skill in the art that other similarcompounds may be prepared by following the teachings set forth in theabove articles and modifying with appropriate art-recognized steps.

Several other derivatives of tetranitrofluorene similarly can beattached at the 20 position of CPT or a CPT analog. Thesetetranitrofluorenes can be synthesized in one step via condensation oftetranitrofluoren-9-one (commercially available from Aldrich) and anamine of the formula NH₂—O-(T)_(n)-X—COOH, wherein (T)_(n) and X are asdefined herein. The imine 2.1 then reacts with CPT or a CPT analog togive the C20 esters 2.2, wherein R₂, R₃, R₄, R₅, and R₆ are as definedherein (Scheme 2). Optionally, the imine double bond in ester 2.2 can bereacted with a reducing agent such as sodium borohydride (NaBH₄) to givethe amine 2.3.

Similarly, other electron-affinic groups such as nitroimidazole,nitrotriazole, nitrothiazole, etc. can be linked at the 20 position ofCPT or CPT analogs. Thus, coupling of CPT or a CPT analog with CDI(1,1′-carbonyldiimidazole) followed by reaction of the intermediate20-carbonylimidazolide with alcohols gives analogs where theradiosensitizing group is attached via a carbonate linkage (X═O). Thelength and nature of the linker between CPT and the electron-affinicgroup may be altered. It is possible to prepare analogs in whichelectron-affinic group is either closer or further away from the CPTmolecule. For example, reaction with 4-nitrobenzoic acid gives thecorresponding 4-nitrobenzoate 3.1 where the electron-affinic group isvery close to the CPT molecule. While reaction with CDI (for conditions,see US Pub. No. US 2002/0040155 A1) followed by2-(2-nitro-imidazol-1-yl)ethanol gives the corresponding carbonate 3.2where the electron-affinic group is away from the CPT molecule. It isalso possible to prepare analogs with multiple radiosensitizing groupsattached to a single linker. For example, reaction of 2-nitroimidazolewith glycidyl chloride provides alcohol A (US Pub. No. US 2002/0040155A1) which then reacts with CPT to give a carbonate 3.3 containing 2radiosensitizing groups linked at C20 (Scheme 3).

The structure of CPT is shown in the following schemes as:

For analogs of CPT, the structure is shown as above and the additionalsubstituent is shown with its position on the CPT molecule.

C9 and C10 Analogs

Electron-affinic groups also can be linked at 9 or 10 positions.Condensation of 9- or 10-amino CPT (J. Med. Chem. 1993, 36, 2689-2700)with nitro-substituted ketones gives the corresponding imines. Forexample, 2,4,5,7-tetranitrofluoren-9-one (commercially available fromAldrich) gives the corresponding imine 4.1 with radiosensitizingtetranitrofluorenyl group at 9 or 10 position (Scheme 4). Reduction ofthe double bond in imine 4.1 with reducing agents such as NaBH₄ followedby acylation of 20-hydroxy group with acyl halide gives the amine 4.2.Several other nitroaldehydes or nitroketones also react similarly.

Alternatively, 9- or 10-hydroxy CPT (J. Med. Chem. 1993,36, 2689-2700)can be converted to the corresponding phenolic esters containingelectron-affinic groups. Depending on the polarity of solvent used(Bioorg. Med. Chem. Lett. 2003, 13, 3739-3741), either mono- or di-esteris formed (Scheme 5). The carboxylic acids 2.1 used in Scheme 2 reactwith either 9- or 10-hydroxy CPT in presence of1-(3-dimethylaminopropyl)-3-ethyl-carbodiimide (EDCI) in a polar solventsuch as dimethylformamide (DMF) to give the corresponding mono-esters5.1. Alternatively, if the reaction is carried out in a nonpolar solventsuch as methylene chloride, the corresponding di-esters 5.2 are formed.The imine bond in mono-ester 5.1 on reduction with reducing agents suchas NaBH₄ followed by acylation of 20-hydroxy group with acyl halidegives the corresponding amine 5.3. The imine bond in di-ester 5.2 onreduction with reducing agents such as NaBH₄ gives the correspondingamine 5.4. Similarly, other carboxylic acids containing electron-affinicgroups can be used in this reaction. Also, CPT analogs that contain 9-or 10-hydroxy group and additional substituents in the molecule can alsobe converted to their di-esters.

C7Analogs

The 7-hydroxyalkyl CPT analogs, where R′ is alkylene (Chem. Pharm. Bull.1991, 39(10) 2574-2580) can be similarly acylated as shown above for the9- or 10-hydroxy analogs, using carboxylic acids 2.1 to give thecorresponding mono-esters 6.1 or di-esters 6.2 (Scheme 6). The iminebond in mono-ester 6.1 on reduction with reducing agents such as NaBH₄followed by acylation of 20-hydroxy group with acyl halide gives thecorresponding amine 6.3. The imine bond in di-ester 6.2 on reductionwith reducing agents such as NaBH₄ gives the corresponding amine 6.4.Similarly, other carboxylic acids containing electron-affinic groups canbe used in this reaction.

C11 and C12 Analogs

11- or 12-hydroxy CPT can be converted to the corresponding phenolicesters containing the electron-affinic groups at 11 or 12 positions.11-hydroxy CPT is known in the literature (U.S. Pat. No. 4,604,463).Starting with 12-amino CPT (J. Med. Chem. 1986, 29, 2358 and J. Med.Chem. 1987, 30, 1774), the corresponding 12-hydroxy CPT can besynthesized using the known two-step method (U.S. Pat. No. 4,604,463).The 11- or 12-hydroxy CPT are similarly acylated as shown above for the7, 9, or 10-hydroxy analogs, using carboxylic acids 2.1 to give thecorresponding mono-esters 7.1 or di-esters 7.2 (Scheme 7). The iminebond in mono-ester 7.1 on reduction with reducing agents such as NaBH₄followed by acylation of 20-hydroxy group with acyl halide gives thecorresponding amine 7.3. The imine bond in di-ester 7.2 on reductionwith reducing agents such as NaBH₄ gives the corresponding amine 7.4.Similarly, other carboxylic acids containing electron-affinic groups canbe used in this reaction. Also, CPT analogs that contain 11 or12-hydroxy group and additional substituents in the molecule can also beused in this reaction.

In addition, the reactions shown in Scheme 3 can also be applied for 7,9, 10, 11, or 12-hydroxy CPT to give the corresponding CPT analogscontaining various other electron-affinic groups.

C5 Analogs

The semi-synthesis of 5-substituted CPT analogs has been reported in theliterature (Bioorg Med Chem Lett. 1995, 5(1), 77-82 and Bioorg Med ChemLett. 1999; 9(12), 1633-1638). One 5-substituted CPT analog,5-(2-hydroxyethoxy) CPT (The Journal of Clinical Pharmacology 2004, 44,723-736), is already in clinical trials. Using the synthetic strategyreported in the above-mentioned references, electron affinic groups canbe linked to the 5 position of a CPT molecule or analog.

Several other CPT analogs containing sugar, phosphosugar, or O-quinonemoiety at C5, C7, C9, C10, C11, C12, or C20 position can also beprepared by attaching those moieties via an ether linkage. These analogscan be obtained via one step coupling reaction of the correspondinghydroxy CPT analog, with a sugar, a phosphosugar, or a quinonerespectively. Representative examples of sugar and phosphosugar aregiven in the definition section above. Representative examples ofquinone include, but are not limited to, unsubstituted and optionallysubstituted benzoquinones, unsubstituted and optionally substitutednaphthoquinones, etc. For example, an unsubstituted benzoquinone can beattached at C9 of CPT via an ether linkage by coupling of 9-hydroxy CPTwith 2-chlorobenzoquinone (commercially available at Sigma-Aldrich).Other examples of commercially available quinones at Sigma-Aldrichinclude, but are not limited to,2,3-Dichloro-5,6-dicyano-1,4-benzoquinone,2,5-Dibromo-6-isopropyl-3-methyl-1,4-benzoquinone, and2,3-Dichloro-1,4-naphthoquinone, etc.

6. Pharmaceutical Composition of the Invention

This aspect of the invention is a pharmaceutical composition useful fortreating cancer in a warm-blooded animal, which composition comprises acompound of the invention, as defined by formula II herein, incombination with a pharmaceutically acceptable excipient. Thecomposition is prepared in accordance with known formulation techniquesto provide a composition suitable for oral, topical, transdermal,rectal, inhalation, or parenteral (intravenous, intramuscular, orintraperitoneal) administration, and the like. Detailed guidance forpreparing compositions of the invention are found by reference to the18^(th) or 19^(th) Edition of Remington's Pharmaceutical Sciences,Published by the Mack Publishing Co., Easton, Pa. 18040. The pertinentportions are incorporated herein by reference.

Unit doses or multiple dose forms are contemplated, each offeringadvantages in certain clinical settings. The unit dose would contain apredetermined quantity of active compound calculated to produce thedesired effect(s) in the setting of treating cancer. The multiple doseform may be particularly useful when multiples of single doses, orfractional doses, are required to achieve the desired ends. Either ofthese dosing forms may have specifications that are dictated by ordirectly dependent upon the unique characteristic of the particularcompound, the particular therapeutic effect to be achieved, and anylimitations inherent in the art of preparing the particular compound fortreatment of cancer.

A unit dose will contain a therapeutically effective amount sufficientto treat cancer in a subject and may contain from about 1.0 to 1000 mgof compound, for example about 50 to 500 mg.

The compound will preferably be administered orally in a suitableformulation as an ingestible tablet, a buccal tablet, capsule, caplet,elixir, suspension, syrup, trouche, wafer, lozenge, and the like.Generally, the most straightforward formulation is a tablet or capsule(individually or collectively designated as an “oral dosage unit”).Suitable formulations are prepared in accordance with a standardformulating techniques available that match the characteristics of thecompound to the excipients available for formulating an appropriatecomposition. A tablet or capsule will contain about 50 to about 500 mgof a compound of Formula (I).

The form may deliver a compound rapidly or may be a sustained-releasepreparation. The compound may be enclosed in a hard or soft capsule, maybe compressed into tablets, or may be incorporated with beverages, foodor otherwise into the diet. The percentage of the final composition andthe preparations may, of course, be varied and may conveniently rangebetween 1 and 90% of the weight of the final form, e.g., tablet. Theamount in such therapeutically useful compositions is such that asuitable dosage will be obtained. Preferred compositions according tothe current invention are prepared so that an oral dosage unit formcontains between about 5 to about 50% by weight (% w) in dosage unitsweighing between 50 and 1000 mg.

The suitable formulation of an oral dosage unit may also contain: abinder, such as gum tragacanth, acacia, corn starch, gelatin; sweeteningagents such as lactose or sucrose; disintegrating agents such as cornstarch, alginic acid and the like; a lubricant such as magnesiumstearate; or flavoring such a peppermint, oil of wintergreen or thelike. Various other material may be present as coating or to otherwisemodify the physical form of the oral dosage unit. The oral dosage unitmay be coated with shellac, a sugar or both. Syrup or elixir may containthe compound, sucrose as a sweetening agent, methyl and propylparabensas a preservative, a dye and flavoring. Any material utilized should bepharmaceutically-acceptable and substantially non-toxic. Details of thetypes of excipients useful may be found in the nineteenth edition of“Remington: The Science and Practice of Pharmacy,” Mack PrintingCompany, Easton, Pa. See particularly chapters 91-93 for a fullerdiscussion.

A compound may be administered parenterally, e.g., intravenously,intramuscularly, intravenously, subcutaneously, or interperitonically.The carrier or excipient or excipient mixture can be a solvent or adispersive medium containing, for example, various polar or non-polarsolvents, suitable mixtures thereof, or oils. As used herein “carrier”or “excipient” means a pharmaceutically acceptable carrier or excipientand includes any and all solvents, dispersive agents or media,coating(s), antimicrobial agents, iso/hypo/hypertonic agents,absorption-modifying agents, and the like. The use of such substancesand the agents for pharmaceutically active substances is well known inthe art. Except insofar as any conventional media or agent isincompatible with the active ingredient, use in therapeutic compositionsis contemplated. Moreover, other or supplementary active ingredients canalso be incorporated into the final composition.

Solutions of the compound may be prepared in suitable diluents such aswater, ethanol, glycerol, liquid polyethylene glycol(s), various oils,and/or mixtures thereof, and others known to those skilled in the art.

The pharmaceutical forms suitable for injectable use include sterilesolutions, dispersions, emulsions, and sterile powders. The final formmust be stable under conditions of manufacture and storage. Furthermore,the final pharmaceutical form must be protected against contaminationand must, therefore, be able to inhibit the growth of microorganismssuch as bacteria or fungi. A single intravenous or intraperitoneal dosecan be administered. Alternatively, a slow long term infusion ormultiple short term daily infusions may be utilized, typically lastingfrom 1 to 8 days. Alternate day or dosing once every several days mayalso be utilized.

Sterile, injectable solutions are prepared by incorporating a compoundin the required amount into one or more appropriate solvents to whichother ingredients, listed above or known to those skilled in the art,may be added as required. Sterile injectable solutions are prepared byincorporating the compound in the required amount in the appropriatesolvent with various other ingredients as required. Sterilizingprocedures, such as filtration, then follow. Typically, dispersions aremade by incorporating the compound into a sterile vehicle which alsocontains the dispersion medium and the required other ingredients asindicated above. In the case of a sterile powder, the preferred methodsinclude vacuum drying or freeze drying to which any required ingredientsare added.

In all cases the final form, as noted, must be sterile and must also beable to pass readily through an injection device such as a hollowneedle. The proper viscosity may be achieved and maintained by theproper choice of solvents or excipients. Moreover, the use of molecularor particulate coatings such as lecithin, the proper selection ofparticle size in dispersions, or the use of materials with surfactantproperties may be utilized.

Prevention or inhibition of growth of microorganisms may be achievedthrough the addition of one or more antimicrobial agents such aschlorobutanol, ascorbic acid, parabens, thermerosal, or the like. It mayalso be preferable to include agents that alter the tonicity such assugars or salts.

In some cases, e.g., where a compound of the invention is quite waterinsoluble, it may be useful to provide liposomal delivery. The systemrestrains the compound of the invention by incorporating, encapsulating,surrounding, or entrapping the compound of the invention in, on, or bylipid vesicles or liposomes, or by micelles.

Usefully, the compound of the invention is solubilized in liposomes. Theliposomes may include, for example, lipids such as cholesterol,phospholipids, or micelles comprised of surfactant such as, for example,sodium dodecylsulfate, octylphenolpolyoxyethylene glycol, or sorbitanmono-oleate. Typically, the compound of the invention binds to the lipidbilayer membrane of the liposome with high affinity. The liposome boundprodrug can preferably intercalate between the acyl chains of the lipid.The lactone ring of the camptothecin-derivative, membrane-bound compoundof the invention is thereby removed from the aqueous environment insideand outside of the liposome and further protected from hydrolysis. Sincethe liposome-bound drug is protected from hydrolysis, the antitumoractivity of the drug is preserved. For a compound of the invention whichhas a lower affinity for the liposome membrane and thus disassociatesfrom the liposome membrane to reside in the interior of liposome, the pHof the interior of the liposomes may be reduced thereby preventinghydrolysis of such compound of the invention.

A useful group of liposomal delivery systems which may be used inaccordance with the present invention include those described in U.S.Pat. Nos. 5,552,156 and 5,736,156, which are herein incorporated intheir entireties by reference. Other liposomal delivery systems whichmay be employed in accordance with the present invention includeliposomes containing active agents aggregated with lipids or surfactantsas described in U.S. Pat. Nos. 5,827,533 and 5,882,679; lipid vesiclesformed with alkyl ammonium fatty acid salts as described in U.S. Pat.No. 5,874,105; liposomes for encapsulating active agent dry powdercompositions as described in U.S. Pat. No. 5,783,211; liposomal drugdelivery systems for topical patches as described in U.S. Pat. No.5,718,914; the liposomes described in U.S. Pat. No. 5,631,237; theliposome and lipid complex compositions described in U.S. Pat. Nos.5,549,910 and 5,077,057; the liposomes used for sustained release ofsteroidal drugs as described in U.S. Pat. No. 5,043,165; the liposomesdescribed in U.S. Pat. No. 5,013,556; and the liposomes described inU.S. Pat. No. 4,663,161; all of which are herein incorporated in theirentireties by reference.

Unilamellar liposomes, also referred to as single lamellar vesicles, arespherical vesicles comprised of one lipid bilayer membrane which definesa closed compartment. The bilayer membrane is composed of two layers oflipids; an inner layer and an outer layer. The outer layer of lipidmolecules are oriented with their hydrophilic head portions toward theexternal aqueous environment and their hydrophobic tails pointeddownward toward interior of the liposome. The inner layer of lipid laysdirectly beneath the outer layer; the lipids are oriented with theirheads facing the aqueous interior of the liposome and their tails towardthe tails of outer layer of lipid.

Multilamellar liposomes, also referred to as multilamellar vesicles, arecomposed of more than one lipid bilayer membrane, which membranes definemore than one closed compartment. The membranes are concentricallyarranged so that the different membranes are separated by compartmentsmuch like an onion skin.

Thus, some or all of the compound of the invention is located in one ormore of the compartments of a liposome or micelle, or the compound ofthe invention is bound to the membrane of the liposome. Where a compoundis bound to a lipid membrane, at least the lactone ring of some or allof the compound of the invention binds to the lipid membrane of theliposome, and where the liposome contains more than one bilayer membranethe compound of the invention is bound to at least 1 membrane. Thosecompounds of the invention that have a high affinity for such membranetend to remain bound to the membrane. Those compounds of the inventionwith a low affinity for liposome membrane, will at least partiallydisassociate from the liposome membrane and reside in the liposomecompartment.

Micelles as defined herein are spherical receptacles comprised of asingle, monolayer membrane which defines a closed compartment and themembrane is comprised of surfactant molecules oriented so that thehydrocarbon tails are oriented toward the compartment and the polar headportions are oriented toward the external aqueous environment. Thecompounds of the invention, when associated with micelles, are either inthe compartment, bound to the micelle membrane, or bound to the outsidesurface of the micelle.

Liposomes have been used successfully to administer medications tocancer patients, and have been shown to be useful clinically in thedelivery of anticancer drugs such as doxorubicin, daunorubicin, andcisplatinum complexes. Forssen, et al., Cancer Res. 1992, 52: 3255-3261;Perex-Soler, et al., Cancer Res. 1990, 50: 4260-4266; and, Khokhar, etal., J. Med. Chem. 1991, 34: 325-329, all of which are incorporatedherein in their entireties by reference.

Similarly, micelles have also been used to deliver medications topatients, (Broden et al., Acta Pharm Suec. 19: 267-284 (1982)) andmicelles have been used as drug carriers and for targeted drug delivery,(D. D. Lasic, Nature 335: 279-280 (1992); and, Supersaxo et al., PharmRes. 8: 1280-1291 (1991)), including cancer medications, (Fung et al.,Biomater. Artif. Cells. Artif. Organs 16: 439 et seq. (1988); andYokoyama et al., Cancer Res. 51: 3229-3236 (1991)), all of which areincorporated herein in their entireties by reference.

The liposomes and/or micelles containing the compound of the inventioncan be administered to a cancer patient, typically intravenously. Theliposomes and/or micelles are carried by the circulatory system to thecancer cells where the membrane of the vesicle fuses to the membrane ofthe cancer cell thereby releasing the compound of the invention to thecancer cell, or where the liposomes and/or micelles to be taken up bythe cancer cells, the compound of the invention diffuses from theliposomes and/or micelles to be taken up by the cancer cells.

Any lipid mixture of lipids which forms liposomes and/or micelles issuitable for use in the present invention. Phosphatidylcholines,including, for example, L-α-dimyristoylphosphatidylcholine (DPMC),1-α-dipalmitoylphosphatidylcholine (DPPC) andL-α-distearoylphosphatidylcholine (DSPC) are suitable. Also,phosphatidylglycerols, including, for example,L-α-dimyristoylphosphatidylglycerol (DMPG) are suitable. The DMPC andDMPG are both fluid phase at 37, for example,L-α-dimyristoylphosphatidylglycerol (DMPG) are suitable. The DMPC andDMPG are both fluid phase at 37° C., while DSPC is solid phase at 37° C.Since the presence of negatively charged lipid in the liposome membranecauses the liposomes to repel each other, small amounts, such as, forexample about 10%, of an negatively charged lipid, such asdistearolphosphotidylglycerol (DSPG), may be incorporated in to the DSPCliposomes. Other suitable phospholipids include:phosphatidyl-ethanolamides, phosphatidylinositols, and phosphatidicacids containing lauric, myristic, palmitic, palmitoleic, stearic,oleic, linoleic, arachidonic, behenic and lignoceric acid. Anothersuitable lipid includes cholesterol.

U.S. Pat. No. 6,096,336 provides further guidance for preparingliposomal compositions useful in this invention and is incorporatedherein by reference.

The present invention is not limited in scope by the exemplifiedembodiments, which are intended as illustrations of single aspects ofthe invention only. Any methods that are functionally equivalent arewithin the scope of the invention. Various modifications of theinvention in addition to those described herein will become apparent tothose skilled in the art from the foregoing description and accompanyingfigures. Such modifications fall within the scope of the appendedclaims.

EXAMPLES

In the following descriptions, optical rotations were measured at 20-25°C. with an Atago Polax-2L polarimeter. ¹H and ¹³C spectra were recordedon a Varian Unity Inova NMR Spectrometer operating at 300 and 75 MHz,respectively. Chemical shifts are referenced to the solvent used (7.27and 77.23 ppm for CDCl₃, 3.31 and 49.15 ppm for CD₃OD) unless otherwisestated. Electrospray-ionization mass spectra (ESIMS) were acquired usingThermo Finnigan LCQ Advantage mass spectrometer.

The chromatographic purity of the products was assessed using WatersAlliance 2695 separation modules with Waters 2996 PDA detector HPLCsystem using a gradient of water and acetonitrile, and TLC on silica gel60 F₂₅₄ (APCO, China). TLC plates were visualized by using either the UVlamp or anisaldehyde stain (by volume: 93% ethanol, 3.5% sulfuric acid,1% acetic acid and 2.5% anisaldehyde). Chromatographic separations wereperformed using silica gel (APCO, China; 300-400 μm mesh size).

All chemicals were obtained from commercial sources and used as receivedunless otherwise stated. All experiments were conducted under anatmosphere of dry argon. Only the 20(S)-camptothecin (CPT) derivativewas used in all the experiments.

Unless otherwise stated all temperatures are in degrees Celsius. Also,in these examples and elsewhere, abbreviations have the followingmeanings:

pμL=microliter

Boc=tert-butoxycarbonyl

d=doublet

dd=double doublet

g=gram

kg=kilogram

hr=hour

Hz=hertz

L=liter

M=molar

nM=nanomolar

m=multiplet

m/z=mass to charge ratio

EtOH=ethanol

H₂SO₄=sulfuric acid

HNO₃=nitric acid

Et₂O=diethyl ether

EtOAc=ethyl acetate

MeOH=methanol

mg=milligram

MHz=mega Hertz

min=minute

mL=milliliter

mmol=millimole

mol=mole

N=normal

NaOEt=sodium ethoxide

NMR=nuclear magnetic resonance

q=quartet

s=singlet

t=triplet

(NH₄)₂SO₄=ammonium sulfate

Et₂O=diethyl ether

Na₂SO₄=sodium sulfate

HCl=hydrochloric acid

AcOH=acetic acid

DCM=dichloromethane

DMAP=4-dimethylaminopyridine

ESI MS=electrospray Ionization Mass Spectrometry

NaHCO₃=sodium bicarbonate

TFA=trifluoroacetic acid

Hobt=1-hydroxy benzotriazole

DCC=N,N′-dicyclohexylcarbodiimide

DIC=N,N′-diisopropylcarbodiimide

DMF=N,N-dimethylformamide

rt=room temperature

aq=aqueous

ppm=parts per million

μm=micrometer

Gy=gray

Synthesis of Staring Materials A. 2,4,5,7-tetranitrofluorenone (1, TNF)

The synthesis of 2,4,5,7-tetranitrofluorenone (1, TNF)was adapted fromMelvin, S et al., Organic Synthesis, 1962, 42, 95-6. Briefly, to asuspension of 9-fluorenone (62.5 g, 346.84 mmol) in conc. H₂SO₄ (300 mL)was added fuming nitric acid (236 mL, 5.205 mol) slowly. The reactionmixture was heated to gentle reflux (˜140° C. bath temp) for 8 hr, thenstirred at rt overnight. The reaction mixture was poured into water (3L) and the light yellow precipitate was washed with water, dried at rtovernight, then at low vacuum at 80° C. for 2 days to afford 101.8 g ofTNF 1 as yellow solid (81%). ¹H NMR (acetone-d6): δ 9.05 (s, 2H, Ar),8.87 (s, 2H, Ar); M.p. 253-255° C.

B. (±)-α-(isopropylideneaminooxy)propionic acid (2)

The synthesis of (±)-α-(isopropylideneaminooxy)propionic acid (2) wasadapted from Melvin, S et al., Organic Syntheses, 1973, Coll. Vol. 5,1029-37. Briefly, to a freshly prepared 1M NaOEt solution (35g in 1 L)was added acetone oxime (110 g, 1.505 mol) and cooled to 0° C. Ethylα-bromopropionate (175 mL, 1.347 mol) was added at a rate that such thatthe temperature of the reaction mixture did not rise above 20° C. After18 hr at rt, the mixture was filtered and the filtrate was concentratedto approximately 500 mL. Water (500 mL) was added and the mixture wasextracted with 1:1 benzene:Et₂O (3×150 mL). The combined extracts werewashed with water (500 mL), dried over Na₂SO₄ and the solvent wasremoved and the oily residue was distilled to afford 197 g of ethylα-(isopropylideneaminooxy)propionate as a clear oil (83%) ¹H NMR(CDCl₃): δ 4.5 (q, 1H, J=6.9 Hz, CH), 4.1 (m, 2H, J=7.2 Hz, O—CH₂-Me),1.84 (s, 3H, CH₃), 1.61 (s, 3H, CH₃), 1.22 (d, 3H, J=6.9 Hz, CH—CH₃),1.17 (t, 3H,, J=7.2 Hz, —CH₃); B.P. 62-64° C. (4 mm).

The ethyl α-(isopropylideneaminooxy)propionate was added to 5% NaOHsolution (1.2 L) at 70° C. After 20 min, the solution was cooled to rtand acidified to pH 2.0 with 5N HCl solution. Then to the solution wasadded (NH₄)₂SO₄ (500g) and the mixture was extracted with 1:1benzene:Et₂O (2×300 mL). The combined organic extracts were dried overNa₂SO₄ and concentrated to approximately 200 mL. Petroleum ether (500mL) was added and the solution was cooled to −20° C. overnight. Therecrystallized product was recovered by filtration. 80g of product 2 wasrecovered as a white solid (37%). ¹H NMR (CDCl₃): δ 4.64 (q, 1H, J=6.9Hz, CH), 1.93 (s, 3H, CH₃), 1.90 (s, 3H, CH₃), 1.50 (d, 3H, J=6.9 Hz,CH₃); M.p. 59-61° C.

C. (+)-α-(isopropylideneaminooxy)propionic acid (2a)

The synthesis of (+)-α-(isopropylideneaminooxy)propionic acid (2a) wasadapted from Melvin, S et al., Organic Syntheses, 1973, Coll. Vol. 5,1029-37. Briefly, (−)-ephedrine hydrochloride (40 g, 200 mmol) wasdissolved in water (200 mL) and added 2N NaOH solution (120 mL). Themixture was extracted with EtOAc (3×100 mL), dried over Na₂SO₄ andfiltered. EtOH (50 mL) was added and the mixture was diluted with EtOAc(450 mL). (O)-α-(isopropylideneaminooxy)propionic acid (29 g, 200 mmol)was added and the mixture was allowed to remain undisturbed at 4° C. for16 hr. The crystalline(−)ephedrine-(±)-α-(isopropylideneaminooxy)propionic acid salt wasrecovered by filtration and the dried crystals were recrystallized inEtOAc (250 mL). The crystalline solid was dissolved in water (60 mL) andtreated with 5N HCl solution (14 mL). The solution was extracted with1:1 benzene:Et₂O (3×50 mL). The combined extracts were dried over Na₂SO₄and filtered. The solvent was removed and remaining residue wasrecrystallized in petroleum ether (75 mL) at −20° C. overnight.Recovered 7.6 g of (+)-α-(isopropylideneaminooxy)propionic acid 2a.[α]^(21.4) _(D)=+33.3° (c=1.05).

D. (−)-α-(isopropylideneaminooxy)propionic acid (2b)

The synthesis of (−)-α-(isopropylideneaminooxy)propionic acid (2b) wasadapted from Melvin, S et al., Organic Syntheses, 1973, Coll. Vol. 5,1029-37. Briefly, the EtOAc filtrate from preparation of(+)-.α-(isopropylideneaminooxy)propionic acid was diluted with an equalvolume of petroleum ether and cooled to 0° C. for 16 hr and filtered.The crystalline solid was dissolved in water (60 mL) and treated with 5NHCl solution (14 mL). The solution was extracted with 1:1 benzene:Et₂O(3×50 mL). The combined extracts were dried over Na₂SO₄ and filtered.The solvent was removed and remaining residue was recrystallized inpetroleum ether (75 mL) at −20° C. overnight. 5.2 g of(−)-α-(isopropylideneaminooxy)propionic acid 2b was recovered.[α]^(19.0) _(D)=−33° (c=2.00).

E. (+)-α-(2.4.5.7-Tetranitro-9-fluorenylideneaminooxy)propionic acid(3a, (+)TAPA)

The synthesis of(+)-α-(2.4.5.7-Tetranitro-9-fluorenylideneaminooxy)propionic acid (3a,(+)TAPA) was adapted from Melvin, S et al., Organic Syntheses, 1973,Coll. Vol. 5, 1029-37. Briefly, (+)-α-(isopropylideneaminooxy)propionicacid (12.3 g, 84.73 mmol) and 2,4,5,7-tetranitrofluorenone (25.2 g,70.61 mmol) were dissolved in glacial AcOH (565 mL) and concentratedH₂SO₄ (1.41 mL) was added. The mixture was refluxed at 130° C. for 2 hr.The reaction mixture was added to water (500 mL), cooled to 0° C.overnight and filtered. The solid was dried at rt overnight, followed bydrying under high vacuum at 100° C. overnight to afford 15g of (+)TAPA3a as a yellow solid (77%). ¹H NMR (acetone-d6): δ 9.58 (s, 1H, Ar),8.98 (s, 2H, Ar), 8.92 (s, 1H, Ar), 5.32 (q, 1H, J=6.9 Hz, CH), 1.93 (d,3H, J=6.9 Hz, CH3); M.p. 201-203° C. (dec); [α]²¹ _(D)=−97°.

F. (−)-α-(2.4.5.7-Tetranitro-9-fluorenylideneaminooxy)propionic acid(3b, (−)TAPA)

The synthesis of (−)TAPA was similar to the preparation of (+)TAPA.Briefly, (−)-α-(isopropylideneaminooxy)propionic acid (5 g, 34.44 mmol)and 2,4,5,7-tetranitrofluorenone (8.3 g, 22.96 mmol) were dissolved inglacial AcOH (184 mL) and concentrated H₂SO₄ (0.46 mL) was added. Themixture was refluxed at 130° C. for 2 hr. The reaction mixture was addedto water (100 mL), cooled to 0° C. overnight and filtered. The solid wasdried at rt overnight, followed by drying under high vacuum at 100° C.overnight to afford 8.23 g of (−)TAPA 3b as a yellow solid (80%). ¹H NMR(acetone-d6): δ 9.58 (s, 1H, Ar), 8.98 (s, 2H, Ar), 8.92 (s, 1H, Ar),5.32 (q, 1H, J=6.9 Hz, CH), 1.93 (d, 3H, J=6.9 Hz, CH3); M.p. 201-203°C. (dec); [α]²¹ _(D)=+97°.

G. 2.4.5.7-Tetranitro-9-fluorenylideneaminooxy ethanoic acid (4,TNF-ethanoic acid)

To a solution of tetranitrofluorenone (40g, 111.11 mmol) in glacial AcOH(370 mL) was added carboxymethoxylamine hemihydrochloride (24.3 g,222.22 mmol) and conc. H₂SO₄ (2.22 mL). The mixture was refluxed for 3hr (˜150° C. bath temp) and while the solution was still hot, deionizedwater (100 mL) was added. The mixture was cooled to 0° C. overnight andthe precipitate was recovered by filtration. The solid was washed withwater and dried under high vacuum overnight, followed by drying at 100°C. under high vacuum for 3 days to afford 45.2 g of product 4 as ayellow solid (94%). ¹H NMR (acetone-d6): δ 9.59 (s, 1H, Ar), 9.02 (s,1H, Ar), 8.95 (s, 1H, Ar), 8.93 (s, 1H, Ar), 5.38 (s, 2H, CH₂); ¹³C NMR(acetone-d6): δ 127.01, 123.03, 122.03, 120.44, 73.57. M.p. 203-205° C.,ESIMS: calcd for C₁₅H₇N₅O₁₁ [M−H]⁻ 432.01, found 432, 865.2 (dimer).

H. 9-fluorenylideneaminooxy ethanoic acid (5,9F-ethanoic acid)

To a solution of 9-fluorenone (2 g, 11.10 mmol) in glacial AcOH (56 mL)was added carboxymethoxylamine hemihydrochloride (2.43 g, 22.20 mmol)and conc. H₂SO₄ (221 μL). The mixture was refluxed for 3 hr (˜150° C.bath temp) and while the solution was still hot, deionized water (50 mL)was added. The mixture was cooled to 0° C. overnight and the precipitatewas recovered by filtration. The solid was washed with water and driedunder high vacuum overnight, followed by drying at 100° C. under highvacuum overnight to afford 2.78 g of product 5 as a light yellow solid(99%). ¹H NMR (1:1 CDCl₃:acetone-d6): δ 8.30 (dd, 1H, J=0.9, 7.5 Hz,Ar), 7.66-7.61 (m, 3H, Ar), 7.41-7.17 (m, 4H, Ar), 4.91 (s, 2H, CH₂);¹³C NMR (acetone-d6): δ 131.74, 130.62, 129.82, 128.58, 128.29, 121.72,120.49, 120.38, 71.89; M.p. 231-233° C., ESIMS: calcd for C₁₅H₁₁NO₃[M−H]⁻ 252.07, found 252.3.

I. (±)-9-fluorenylideneaminooxy propionic acid (6,9F-propionic acid)

To a solution of 9-fluorenone (2 g, 11.10 mmol) in glacial AcOH (89 mL)was added (±)-(isopropylideneaminooxy)propionic acid 2 (1.93 g, 13.32mmol) and conc. H₂SO₄ (222 μL). The mixture was refluxed for 3 hr (˜150°C. bath temp) and while the solution was still hot, deionized water (50mL) was added. The mixture was cooled to 0° C. overnight and theprecipitate was recovered by filtration. The solid was washed with waterand dried under high vacuum overnight, followed by drying at 100° C.under high vacuum overnight to afford 2.7 g of product 6 as a lightyellow solid (91%). ¹H NMR (acetone-d6): δ 8.40 (d, 1H, J=7.5 Hz, Ar),7.84-7.77 (m, 2H, Ar), 7.71 (d, 1H, J=8.4 Hz, Ar), 7.54-7.29 (m, 4H,Ar), 5.03 (q, 1H, J=6.9 Hz, CH), 1.70 (d, 1H, J=6.9 Hz, CH₃); ¹³C NMR(acetone-d6): δ 131.67, 130.55, 129.78, 128.58, 128.26, 121.68, 120.46,120.36, 79.12, 16.97; M.p. 174-176° C., ESIMS: calcd for C₁₆H₁₃NO₃[M−H]⁻ 266.09, found 266.1.

Synthesis of Compounds of the Invention

The invention is further understood by reference to the followingexamples, which are intended to be purely exemplary of the invention.

Example 1 10-tert-butoxycarbonyloxycamptothecin (7, Boc-10H-CPT)

(BOC)₂O (12 g, 54.79 mmol) and 10-hydroxy-camptothecin (10 g, 27.40mmol) were dissolved in DMF (137 mL) and pyridine (46 mL) was added. Themixture was stirred at rt overnight. The reaction mixture was dilutedwith DCM (800 mL) and washed with water (3×300 mL), 1 N HCl (3×300 mL)and dried over Na₂SO₄. The solvent was evaporated to give 12g of crudeproduct 7 (94%). ¹H NMR (CDCl₃): δ 8.34 (s, 1H, Ar), 8.25 (s, 1H, Ar),8.21 (s, 1H, Ar), 7.75 (d, 1H, J=2.4 Hz, Ar), 7.67 (s, 1H), 7.66 (dd,J=8.0, 2.4 Hz, 1H, Ar), 5.75 (d, J=16.5 Hz, 1H, —C—CH₂—O—C(O)—), 5.31(d, J=16.5 Hz, 1H, —C—CH₂—O—C(O)—), 5.30 (s, 2H, —C—CH₂—N—), 1.91 (m,J=6 Hz, 2H, CH₂-Me), 1.62 (s, 9H, t-Bu), 1.06 (t, J=6 Hz, 3H, CH₃).

20-O-(TNF-ethanoyl)-Boc-10H-CPT ester (8)

To a solution of TNF-ethanoic acid 4 (4.3 g 9.95 mmol), Boc-10H-CPT 7(3.08 g, 6.63 mmol) and DIC (3.08 mL, 19.89 mmol) in anhydrous DCM (120mL) was added a solution of DMAP (324 mg, 2.65 mmol) in any DCM (13 mL).After 1 hr at rt, DIC (3.08 mL, 19.89 mmol) and TNF-ethanoic acid (1.43g, 3.32 mmol) were added. The reaction was stirred at rt overnight. Themixture was diluted with DCM (200 mL) and washed with 1N HCl (2×150 mL),saturated aq NaHCO₃ solution (2×150 mL), dried over Na₂SO₄, treated withactivated carbon and filtered. The solvent was evaporated and theremaining residue was purified by silica gel column with 50-80%EtOAc:Hexanes to give 5.3 g of 20-O-(TNF-ethanoyl)-Boc-10H-CPT ester 8as a yellow solid (91%). ¹H NMR (acetone-d6) δ 9.5 (s, 1H,tetranitrofluorenone), 8.94 (s, 1H, tetranitrofluorenone), 8.69 (s, 1H,tetranitrofluorenone), 8.60 (s, 1H, tetranitrofluorenone), 8.56 (s, 1H,Ar), 7.94 (d, 1H, J=9.0 Hz, Ar), 7.81 (s, 1H, Ar), 7.59 (dd, 1H, J=2.7,9.0 Hz, Ar), 7.20 (s, 1H), 5.66-5.37 (m, 4H, —C—CH₂—O—C(O)— and—C—CH₂—N—), 5.30 (s, 2H, O—C(O)—CH₂—O—), 2.30 (m, 2H, J=7.2 Hz, CH₂-Me),1.58 (s, 9H, t-Bu), 0.97 (t, 3H, J=7.2 Hz, CH₃); ¹³C NMR (CDCl₃): δ167.12, 166.99, 157.30, 152.13, 150.23, 149.09, 148.54, 146.57, 146.42,144.57, 140.65, 133.93, 131.30, 130.82, 129.34, 128.70, 127.30, 126.29,122.68, 121.66, 121.14, 120.83, 118.68, 95.98, 84.90, 73.70, 67.70,50.39, 32.35, 28.07, 7.95.; M.p. 205-207° C. (dec), ESIMS: calcd forC₄₀H₂₉N₇O₁₇ [M+H]⁺ 880.16, found 880.4.

By substituting other camptothecin analogs for Boc-10H-CPT 7 in step 1of this example other compounds of this invention are prepared. Othercamptothecin analogs include the following:

-   (20S)-9-nitro CPT;-   (20S)-7-chloro-n-propyldimethylsilyl CPT;-   (20S)-10-hydroxy-7-chloro-n-propyldimethylsilyl CPT;-   (20S)-10-acetoxy-7-chloro-n-propyldimethylsilyl CPT;-   (20S)-7-tert-butyldimethylsilyl CPT;-   (20S)-10-hydroxy-7-tert-butyldimethylsilyl CPT;-   (20S)-10-acetoxy-7-tert-butyldimethylsilyl CPT;-   (20S)-9-hydroxy CPT;-   (20S)-9-amino CPT;-   (20S)-10-amino CPT;-   (20S)-9-amino-10-hydroxy CPT;-   (20S)-9-methylamino CPT;-   (20S)-9-chloro CPT;-   (20S)-9-fluoro CPT;-   (20S)-9-piperidino CPT;-   (20S)-9-morpholinomethyl CPT;-   (20S)-9,10-dichloro CPT;-   (20S)-10-bromo CPT;-   (20S)-10-chloro CPT;-   (20S)-10-methyl CPT;-   (20S)-10-fluoro CPT;-   (20S)-10-nitro CPT;-   (20S)-10,11-methylenedioxy CPT;-   (20S)-10-formyl CPT;-   (20S)-10-nonylcarbonyloxy CPT;-   (20S)-10-undecylcarbonyloxy CPT;-   (20S)-10-heptadecylcarbonyloxy CPT;-   (20S)-10-nonadecylcarbonyloxy CPT;-   (20S)-9-nitro-10,11-methylenedioxy CPT;-   (20S)-9-(4-methylpiperazinylmethyl)-10-hydroxy (CPT);-   (20S)-9-[4-(1-piperidino)-1-piperidinomethyl]-10-hydroxy CPT;-   (20S)-9-methyl-10,11-methylenedioxy CPT;-   (20S)-9-chloro-10,11-methylenedioxy CPT;-   (20S)-9-cyano-10,11-methylenedioxy CPT;-   (20S)-9-acetoxy-10,11-methylenedioxy CPT;-   (20S)-9-acetylamino-10,11-methylenedioxy CPT;-   (20S)-9-aminomethyl-10-hydroxy CPT;-   (20S)-9-ethoxymethyl-10-hydroxy CPT;-   (20S)-9-methylaminomethyl-10-hydroxy CPT;-   (20S)-9-n-propylaminomethyl-10-hydroxy CPT;-   (20S)-9-dimethylaminomethyl-10-hydroxy CPT;-   (20S)-9-cyclohexylaminomethyl-10-hydroxy CPT;-   (20S)-9-(2-hydroxyethyl)aminomethyl-10-hydroxy CPT;-   (20S)-9-(trimethylammonio)methyl-10-hydroxy CPT, methanesulfonate;-   (20S)-9-morpholinomethyl-10-hydroxy CPT;-   (20S)-5-(2-hydroxyethoxy) CPT-   (20S)-9-cyanomethyl-10-hydroxy CPT;-   (20S)-CPT-7-aldehyde;-   (20S)-10-methoxy CPT-7-aldehyde;-   (20S)-7-acetoxymethyl CPT;-   (20S)-7-acetoxymethyl-10-methyl CPT;-   (20S)-7-cyano-10-methoxy CPT;-   (20S)-7-cyano CPT;-   (20S)-7-formylethenyl CPT;-   (20S)-7-ethoxycarbonylethenyl CPT;-   (20S)-7-cyanoethenyl CPT;-   (20S)-7-(2,2-dicyanoethenyl) CPT;-   (20S)-7-(2-cyano-2-ethoxycarbonyl)ethenyl CPT;-   (20S)-7-ethoxycarbonylethyl CPT;-   (20S)-7-ethyl CPT;-   (20S)-7-n-propyl CPT;-   (20S)-7-acetoxymethyl CPT;-   (20S)-7-n-propylcarbonyloxymethyl CPT;-   (20S)-7-ethoxycarbonyl CPT;-   (20S)-7-ethyl-10-hydroxy CPT;-   (20S)-7-ethyl-10-acetyloxy CPT;-   (20S)-7-methyl-10-aminocarbonyloxy CPT;-   (20S)-7-n-propyl-10-piperidinocazbonyloxy CPT;-   (20S)-7-ethyl-10-(2-dimethylamino)ethyl CPT; and-   (20S)-7-ethyl-10-carbamoyloxy derivatives of CPT such as-   (20S)-7-ethyl-10-[4(1-piperidino)-piperidino carbonyloxy CPT;-   (20S)-7-ethyl-10-(1-piperazine)carbonyloxy CPT;-   (20S)-7-ethyl-10-(4-1-propylaminocarbonylmethylpiperazine)carbonyloxy    CPT;-   (20S)-7-ethyl-10-[4(1-pyrrolidinyl)piperazine]carbonyloxy CPT;-   (20S)-7-ethyl-10-[(4-(dimethylamino)-1-piperidino]carbonyloxy CPT;-   (20S)-7-ethyl-10-[4-(di-n-propylamino)-1-piperidinol]carbonyloxy    CPT;-   (20S)-7-ethyl-10-[(4-(di-n-butylamino)-1-piperidino]carbonyloxy CPT;-   (20S)-7-ethyl-10-[4-(1-pyrrolidino)-1-piperidino)]carbonyloxy CPT;-   (20S)-7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy CPT;-   (20S)-7-ethyl-10-[N-methyl-N-2-(dimethylamino)ethylamino]carbonyloxy    CPT-   (20S)-7-(tert-butyldimethylsilyl)CPT-   (20S)-7-(tert-butoxyiminomethyl) CPT (Gimatecan)-   (20S)-7-butyl-10,11-methylenedioxy CPT-   (20S)-7-bromomethyl-10-hydroxy CPT-   (20S)-7-butyl-10-amino CPT-   (20S)-7-(tert-butyldimethylsilyl)-10-hydroxy CPT-   (20S)-7-[(2-trimethylsilyl)ethyl)] CPT (Karentican)-   (20S)-7-[(4-fluorophenoxy)acetyloxymethyl] CPT-   (20S)-7-[(4-methoxyphenoxy)acetyloxymethyl] CPT-   (20S)-7-[(4-cyano-3-fluorophenoxy)acetyloxymethyl] CPT-   (20S)-7-[(3,4,5-trimethoxyphenyl)acetyloxymethyl] CPT-   (20S)-10-[(4-cyano-3-fluorophenoxy)acetyloxy] CPT-   (20S)-10-[(3,4,5-trimethoxyphenyl)acetyloxy] CPT-   (20S)-7-(4-methylpiperazinomethylene)-10,11-ethylenedioxy CPT    (Exatecan)-   (20S)-7-[2-(N-isopropylamino)ethyl] CPT (Belotecan)-   (20S)-[5(RS)-(2-hydroxyethoxy)] CPT-   (20S)-7-ethyl-9-allyl-10-hydroxy CPT (29)-   (20S)-7-ethyl-9-allyl-10-methoxy CPT (29)-   (20S)-7-ethyl-9-propyl-10-hydroxy CPT (29)-   (20S)-7-ethyl-9-propyl-10-methoxy CPT (29)-   (20S)-7,9-diethyl-10-hydroxy CPT (29)-   (20S)-7,9-diethyl-10-methoxy CPT (29)-   (20S)-10-(substituted quaternary ammonium salts) CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl CPT-   (20S)-7-(2-hydroxyethylamino)methyl CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10,11-methylenedioxy    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10,11-methylenedioxy    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10,11-methylenedioxy CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-amino CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-amino CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-amino CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-nitro CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-nitro CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-nitro CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10-hydroxy CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10-hydroxy CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10-hydroxy CPT; and the like.

Example 2 20-O-[(+)TAPA]-Boc-11H-CPT ester (9)

To a solution of(+)TAPA 3a (360 mg, 0.81 mmol), Boc-10H-CPT 7 (250 mg,0.54 mmol), Hobt (80 mg, 0.59 mmol) and DIC (250 μL, 1.61 mmol) in anyDCM (10 mL) was added a solution of DMAP (26 mg, 0.22 mmol) in any DCM(1 mL). After 1 hr at rt, DIC (250 μL, 1.61 mmol) and (+)TAPA 3a (120mg, 0.27 mmol) were added. The reaction was stirred at rt overnight. Themixture was diluted with DCM (50 mL) and washed with 1N HCl (2×25 mL),saturated aq NaHCO₃ solution (2×25 mL), dried over Na₂SO₄, treated withactivated carbon and filtered. The solvent was evaporated and theremaining residue was purified by silica gel column with 50-80%EtOAc:Hexanes to give 400 mg of 20-O-[(+)TAPA]-Boc-10H-CPT ester 9 asyellow solid (85%). ¹H NMR (CDCl₃) δ 9.40 (s, 1H, Ar), 8.85 (s, 1H, Ar),8.54 (s, 1H, Ar), 8.33 (s, 2H, Ar), 7.83-7.58 (m, 3H), 7.17 (s, 1H),5.68 (d, 1H, J=17.4 Hz, —C—CH₂—O—C(O)—), 5.52-5.42 (m, 2H,—C—CH₂—O—C(O)— and O—C(O)—CH(Me)-O—), 5.28 (s, 2H, —C—CH₂—N—), 2.55-2.20(dm, 2H, CH₂-Me), 1.87 (d, 3H, J=7.2 Hz, CH₃), 1.63 (s, 9H, t-Bu), 0.97(t, 3H, J=7.2 Hz, CH₃); ¹³C NMR (acetone-d6): δ 169.05, 150.30, 149.05,146.40, 146.22, 144.54, 131.18, 130.63, 129.36, 127.26, 126.40, 122.55,121.32, 120.54, 118.77, 95.92, 81.03, 67.81, 50.36, 32.48, 28.09, 17.28,7.95; M.p. 210-215° C. (dec); ESIMS: calcd for C₄₁H₃₁N₇O₁₇ [M+H]⁺894.18, found 894.3.

The 20-O-[(+)TAPA]-Boc-10H-CPT ester 7 (4 g, 4.47 mmol) was dissolved inTFA (90 mL). After stirring at rt for 1 hr, bis-(dimethylamine)-methane(30 mL) was added slowly. The mixture was stirred at rt for 45 min andthe crude product was precipitated by addition to water. Filtered andthe precipitate was dissolved in DCM (300 mL), washed with saturatedNaHCO₃ solution (3×200 mL, the solution turned red), dried over Na₂SO₄,filtered and the solvent was removed. The dark red solid was dissolvedin MeOH (100 mL) and added 25 mL of 2M HCl in Et₂O. Filtered and theyellow solid was dried under vacuum to afford 2.88 g of 10 ashydrochloride salt (73%). ¹H NMR (1:1 CDCl₃:CD₃OD): δ9.22 (s, 1H, Ar),8.62 (s, 2H, Ar), 8.31 (s, 1H, Ar), 8.21 (s, 1H, Ar), 7.76 (d, 1H, J=9.3Hz, Ar), 7.37 (d, 1H, J=9.3 Hz, Ar), 7.29 (s, 1H), 5.46-5.19 (m, 3H),5.13 (s, 2H, —C—CH₂—N—), 4.60 (m, 2H), 2.77 (s, 3H, —N—CH3), 2.72 (s,3H, —N—CH₃), 2.05 (dm, 2H, J=7.5 Hz, —CH₂-Me), 1.65 (d, 3H, J=7.2 Hz,CH3), 0.80 (t, 3H, J=7.5 Hz, CH₃); M.p. 210-213° C. (dec); ESIMS: calcdfor C₃₉H₃₀N₈O₁₅ [M+H]⁺ 851.18, found 851.4.

By substituting other camptothecin analogs for Boc-10H-CPT 7 in step 1of this example other compounds of this invention are prepared. Othercamptothecin analogs include the following:

-   (20S)-9-nitro CPT;-   (20S)-7-chloro-n-propyldimethylsilyl CPT;-   (20S)-10-hydroxy-7-chloro-n-propyldimethylsilyl CPT;-   (20S)-10-acetoxy-7-chloro-n-propyldimethylsilyl CPT;-   (20S)-7-tert-butyldimethylsilyl CPT;-   (20S)-10-hydroxy-7-tert-butyldimethylsilyl CPT;-   (20S)-10-acetoxy-7-tert-butyldimethylsilyl CPT;-   (20S)-9-hydroxy CPT;-   (20S)-9-amino CPT;-   (20S)-10-amino CPT;-   (20S)-9-amino-10-hydroxy CPT;-   (20S)-9-methylamino CPT;-   (20S)-9-chloro CPT;-   (20S)-9-fluoro CPT;-   (20S)-9-piperidino CPT;-   (20S)-9-morpholinomethyl CPT;-   (20S)-9,10-dichloro CPT;-   (20S)-10-bromo CPT;-   (20S)-10-chloro CPT;-   (20S)-10-methyl CPT;-   (20S)-10-fluoro CPT;-   (20S)-10-nitro CPT;-   (20S)-10,11-methylenedioxy CPT;-   (20S)-10-formyl CPT;-   (20S)-10-nonylcarbonyloxy CPT;-   (20S)-10-undecylcarbonyloxy CPT;-   (20S)-10-heptadecylcarbonyloxy CPT;-   (20S)-10-nonadecylcarbonyloxy CPT;-   (20S)-9-nitro-10,11-methylenedioxy CPT;-   (20S)-9-(4-methylpiperazinylmethyl)-10-hydroxy (CPT);-   (20S)-9-[4-(1-piperidino)-1-piperidinomethyl]-10-hydroxy CPT;-   (20S)-9-methyl-10,11-methylenedioxy CPT;-   (20S)-9-chloro-10,11-methylenedioxy CPT;-   (20S)-9-cyano-10,11-methylenedioxy CPT;-   (20S)-9-acetoxy-10,11-methylenedioxy CPT;-   (20S)-9-acetylamino-10,11-methylenedioxy CPT;-   (20S)-9-aminomethyl-10-hydroxy CPT;-   (20S)-9-ethoxymethyl-10-hydroxy CPT;-   (20S)-9-methylaminomethyl-10-hydroxy CPT;-   (20S)-9-n-propylaminomethyl-10-hydroxy CPT;-   (20S)-9-dimethylaminomethyl-10-hydroxy CPT;-   (20S)-9-cyclohexylaminomethyl-10-hydroxy CPT;-   (20S)-9-(2-hydroxyethyl)aminomethyl-10-hydroxy CPT;-   (20S)-9-(trimethylammonio)methyl-10-hydroxy CPT, methanesulfonate;-   (20S)-9-morpholinomethyl-10-hydroxy CPT;-   (20S)-5-(2-hydroxyethoxy) CPT-   (20S)-9-cyanomethyl-10-hydroxy CPT;-   (20S)-CPT-7-aldehyde;-   (20S)-10-methoxy CPT-7-aldehyde;-   (20S)-7-acetoxymethyl CPT;-   (20S)-7-acetoxymethyl-10-methyl CPT;-   (20S)-7-cyano-10-methoxy CPT;-   (20S)-7-cyano CPT;-   (20S)-7-formylethenyl CPT;-   (20S)-7-ethoxycarbonylethenyl CPT;-   (20S)-7-cyanoethenyl CPT;-   (20S)-7-(2,2-dicyanoethenyl) CPT;-   (20S)-7-(2-cyano-2-ethoxycarbonyl)ethenyl CPT;-   (20S)-7-ethoxycarbonylethyl CPT;-   (20S)-7-ethyl CPT;-   (20S)-7-n-propyl CPT;-   (20S)-7-acetoxymethyl CPT;-   (20S)-7-n-propylcarbonyloxymethyl CPT;-   (20S)-7-ethoxycarbonyl CPT;-   (20S)-7-ethyl-10-hydroxy CPT;-   (20S)-7-ethyl-10-acetyloxy CPT;-   (20S)-7-methyl-10-aminocarbonyloxy CPT;-   (20S)-7-n-propyl-10-piperidinocazbonyloxy CPT;-   (20S)-7-ethyl-10-(2-dimethylamino)ethyl CPT; and-   (20S)-7-ethyl-10-carbamoyloxy derivatives of CPT such as-   (20S)-7-ethyl-10-[4(1-piperidino)-piperidino carbonyloxy CPT;-   (20S)-7-ethyl-10-(1-piperazine)carbonyloxy CPT;-   (20S)-7-ethyl-10-(4-1-propylaminocarbonylmethylpiperazine)carbonyloxy    CPT;-   (20S)-7-ethyl-10-[4(1-pyrrolidinyl)piperazine]carbonyloxy CPT;-   (20S)-7-ethyl-10-[(4-(dimethylamino)-1-piperidino]carbonyloxy CPT;-   (20S)-7-ethyl-10-[4-(di-n-propylamino)-1-piperidinol]carbonyloxy    CPT;-   (20S)-7-ethyl-10-[(4-(di-n-butylamino)-1-piperidino]carbonyloxy CPT;-   (20S)-7-ethyl-10-[4-(1-pyrrolidino)-1-piperidino)]carbonyloxy CPT;-   (20S)-7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy CPT;-   (20S)-7-ethyl-10-[N-methyl-N-2-(dimethylamino)ethylamino]carbonyloxy    CPT-   (20S)-7-(tert-butyldimethylsilyl)CPT-   (20S)-7-(tert-butoxyiminomethyl) CPT (Gimatecan)-   (20S)-7-butyl-10,11-methylenedioxy CPT-   (20S)-7-bromomethyl-10-hydroxy CPT-   (20S)-7-butyl-10-amino CPT-   (20S)-7-(tert-butyldimethylsilyl)-10-hydroxy CPT-   (20S)-7-[(2-trimethylsilyl)ethyl)] CPT (Karentican)-   (20S)-7-[(4-fluorophenoxy)acetyloxymethyl] CPT-   (20S)-7-[(4-methoxyphenoxy)acetyloxymethyl] CPT-   (20S)-7-[(4-cyano-3-fluorophenoxy)acetyloxymethyl] CPT-   (20S)-7-[(3,4,5-trimethoxyphenyl)acetyloxymethyl] CPT-   (20S)-10-[(4-cyano-3-fluorophenoxy)acetyloxy] CPT-   (20S)-10-[(3,4,5-trimethoxyphenyl)acetyloxy] CPT-   (20S)-7-(4-methylpiperazinomethylene)-10,11-ethylenedioxy CPT    (Exatecan)-   (20S)-7-[2-(N-isopropylamino)ethyl] CPT (Belotecan)-   (20S)-[5(RS)-(2-hydroxyethoxy)] CPT-   (20S)-7-ethyl-9-allyl-10-hydroxy CPT (29)-   (20S)-7-ethyl-9-allyl-10-methoxy CPT (29)-   (20S)-7-ethyl-9-propyl-10-hydroxy CPT (29)-   (20S)-7-ethyl-9-propyl-10-methoxy CPT (29)-   (20S)-7,9-diethyl-10-hydroxy CPT (29)-   (20S)-7,9-diethyl-10-methoxy CPT (29)-   (20S)-10-(substituted quaternary ammonium salts) CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl CPT-   (20S)-7-(2-hydroxyethylamino)methyl CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10,11-methylenedioxy    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10,11-methylenedioxy    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10,11-methylenedioxy CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-amino CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-amino CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-amino CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-nitro CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-nitro CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-nitro CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10-hydroxy CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10-hydroxy CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10-hydroxy CPT; and the like.

Example 3

To a solution of(−)TAPA 3b (1.44 g, 3.23 mmol), Boc-10H-CPT 7 (1 g, 2.15mmol), Hobt (320 mg, 2.37 mmol) and DCC (1.33 g, 6.45 mmol) in any DCM(40 mL) was added a solution of DMAP (105 mg, 0.86 mmol) in any DCM (3mL). After 1 hr at rt, DCC (1.33 g, 6.45 mmol) and (−)TAPA 3b (400 mg,0.84 mmol) were added. The reaction was stirred at rt overnight. Themixture was filtered, diluted with DCM (100 mL) and washed with 1N HCl(2×100 mL), saturated aq NaHCO₃ solution (2×100 mL), dried over Na₂SO₄,treated with activated carbon and filtered. The solvent was evaporatedand the remaining residue was purified by silica gel column with 50-80%EtOAc:Hexanes to give 1.47 g of 20-O-[(−)TAPA]-Boc-10H-CPT ester 11 as ayellow solid (78%). ¹H NMR (CDCl₃) δ 9.52 (s, 1H, Ar), 8.99 (s, 1H, Ar),8.48 (s, 1H, Ar), 8.33 (s, 2H, Ar), 7.83-7.58 (m, 3H), 7.09 (s, 1H),5.68 (d, 1H, J=17.4 Hz, —C—CH₂—O—C(O)—), 5.52-5.42 (m, 2H,—C—CH₂—O—C(O)— and O—C(O)—CH(Me)-O—), 5.28 (s, 2H, —C—CH₂—N—), 2.55-2.20(dm, 2H, CH₂-Me), 1.96 (d, 3H, J=7.2 Hz, CH₃), 1.63 (s, 9H, t-Bu), 0.97(t, 3H, J=7.2 Hz, CH₃); M.p. 210-215° C. (dec); ESIMS: calcd forC₄₁H₃₁N₇O₁₇ [M+H]⁺ 894.18, found 894.3.

The 20-O-[(−)TAPA]-Boc-10H-CPT ester 8 (1.3 g, 1.48 mmol) was dissolvedin TFA (15 mL). After stirring at rt for 1 hr,bis-(dimethylamine)-methane (7.5 mL) was added slowly. The mixture wasstirred at rt for 45 min and the crude product was precipitated byaddition to water. Filtered and the precipitate was dissolved in DCM (75mL), washed with saturated NaHCO₃ solution (2×50 mL, the solution turnedred), dried over Na₂SO₄, filtered and the solvent was removed. The darkred solid was dissolved in MeOH (20 mL) and added 10 mL of 2M HCl inEt₂O. The solvent was evaporated and the residue was purified by silicagel column with 5-20% MeOH:DCM to afford 786 mg of 12 as hydrochloridesalt (60%). ¹H NMR (CD₃OD): δ9.55 (s, 1H, Ar), 9.07 (s, 1H, Ar), 8.77(s, 1H, Ar), 8.26 (s, 1H, Ar), 8.05 (s, 1H, Ar), 7.67 (d, 1H, J=9.0 Hz,Ar), 7.57-7.52 (m, 2H, Ar), 7.21 (s, 1H), 5.70-5.50 (m, 3H), 5.31 (s,2H, —C—CH₂—N—), 4.60 (m, 2H), 3.07 (s, 6H, —N—CH3), 2.38 (dm, 2H, J=7.2Hz, —CH₂-Me), 1.93 (d, 3H, J=6.6 Hz, CH₃), 0.98 (t, 3H, J=7.2 Hz, CH₃);ESIMS: calcd for C₃₉H₃₀N₈O₁₅ [M+H]⁺ 851.18, found 851.4.

By substituting other camptothecin analogs for Boc-10H-CPT 7 in step 1of this example other compounds of this invention are prepared. Othercamptothecin analogs include the following:

-   (20S)-9-nitro CPT;-   (20S)-7-chloro-n-propyldimethylsilyl CPT;-   (20S)-10-hydroxy-7-chloro-n-propyldimethylsilyl CPT;-   (20S)-10-acetoxy-7-chloro-n-propyldimethylsilyl CPT;-   (20S)-7-tert-butyldimethylsilyl CPT;-   (20S)-10-hydroxy-7-tert-butyldimethylsilyl CPT;-   (20S)-10-acetoxy-7-tert-butyldimethylsilyl CPT;-   (20S)-9-hydroxy CPT;-   (20S)-9-amino CPT;-   (20S)-10-amino CPT;-   (20S)-9-amino-10-hydroxy CPT;-   (20S)-9-methylamino CPT;-   (20S)-9-chloro CPT;-   (20S)-9-fluoro CPT;-   (20S)-9-piperidino CPT;-   (20S)-9-morpholinomethyl CPT;-   (20S)-9,10-dichloro CPT;-   (20S)-10-bromo CPT;-   (20S)-10-chloro CPT;-   (20S)-10-methyl CPT;-   (20S)-10-fluoro CPT;-   (20S)-10-nitro CPT;-   (20S)-10,11-methylenedioxy CPT;-   (20S)-10-formyl CPT;-   (20S)-10-nonylcarbonyloxy CPT;-   (20S)-10-undecylcarbonyloxy CPT;-   (20S)-10-heptadecylcarbonyloxy CPT;-   (20S)-10-nonadecylcarbonyloxy CPT;-   (20S)-9-nitro-10,11-methylenedioxy CPT;-   (20S)-9-(4-methylpiperazinylmethyl)-10-hydroxy (CPT);-   (20S)-9-[4-(1-piperidino)-1-piperidinomethyl]-10-hydroxy CPT;-   (20S)-9-methyl-10,11-methylenedioxy CPT;-   (20S)-9-chloro-10,11-methylenedioxy CPT;-   (20S)-9-cyano-10,11-methylenedioxy CPT;-   (20S)-9-acetoxy-10,11-methylenedioxy CPT;-   (20S)-9-acetylamino-10,11-methylenedioxy CPT;-   (20S)-9-aminomethyl-10-hydroxy CPT;-   (20S)-9-ethoxymethyl-10-hydroxy CPT;-   (20S)-9-methylaminomethyl-10-hydroxy CPT;-   (20S)-9-n-propylaminomethyl-10-hydroxy CPT;-   (20S)-9-dimethylaminomethyl-10-hydroxy CPT;-   (20S)-9-cyclohexylaminomethyl-10-hydroxy CPT;-   (20S)-9-(2-hydroxyethyl)aminomethyl-10-hydroxy CPT;-   (20S)-9-(trimethylammonio)methyl-10-hydroxy CPT, methanesulfonate;-   (20S)-9-morpholinomethyl-10-hydroxy CPT;-   (20S)-5-(2-hydroxyethoxy) CPT-   (20S)-9-cyanomethyl-10-hydroxy CPT;-   (20S)-CPT-7-aldehyde;-   (20S)-10-methoxy CPT-7-aldehyde;-   (20S)-7-acetoxymethyl CPT;-   (20S)-7-acetoxymethyl-10-methyl CPT;-   (20S)-7-cyano-10-methoxy CPT;-   (20S)-7-cyano CPT;-   (20S)-7-formylethenyl CPT;-   (20S)-7-ethoxycarbonylethenyl CPT;-   (20S)-7-cyanoethenyl CPT;-   (20S)-7-(2,2-dicyanoethenyl) CPT;-   (20S)-7-(2-cyano-2-ethoxycarbonyl)ethenyl CPT;-   (20S)-7-ethoxycarbonylethyl CPT;-   (20S)-7-ethyl CPT;-   (20S)-7-n-propyl CPT;-   (20S)-7-acetoxymethyl CPT;-   (20S)-7-n-propylcarbonyloxymethyl CPT;-   (20S)-7-ethoxycarbonyl CPT;-   (20S)-7-ethyl-10-hydroxy CPT;-   (20S)-7-ethyl-10-acetyloxy CPT;-   (20S)-7-methyl-10-aminocarbonyloxy CPT;-   (20S)-7-n-propyl-10-piperidinocazbonyloxy CPT;-   (20S)-7-ethyl-10-(2-dimethylamino)ethyl CPT; and-   (20S)-7-ethyl-10-carbamoyloxy derivatives of CPT such as-   (20S)-7-ethyl-10-[4(1-piperidino)-piperidino carbonyloxy CPT;-   (20S)-7-ethyl-10-(1-piperazine)carbonyloxy CPT;-   (20S)-7-ethyl-10-(4-1-propylaminocarbonylmethylpiperazine)carbonyloxy    CPT;-   (20S)-7-ethyl-10-[4(1-pyrrolidinyl)piperazine]carbonyloxy CPT;-   (20S)-7-ethyl-10-[(4-(dimethylamino)-1-piperidino]carbonyloxy CPT;-   (20S)-7-ethyl-10-[4-(di-n-propylamino)-1-piperidinol]carbonyloxy    CPT;-   (20S)-7-ethyl-10-[(4-(di-n-butylamino)-1-piperidino]carbonyloxy CPT;-   (20S)-7-ethyl-10-[4-(1-pyrrolidino)-1-piperidino)]carbonyloxy CPT;-   (20S)-7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy CPT;-   (20S)-7-ethyl-10-[N-methyl-N-2-(dimethylamino)ethylamino]carbonyloxy    CPT-   (20S)-7-(tert-butyldimethylsilyl)CPT-   (20S)-7-(tert-butoxyiminomethyl) CPT (Gimatecan)-   (20S)-7-butyl-10,11-methylenedioxy CPT-   (20S)-7-bromomethyl-10-hydroxy CPT-   (20S)-7-butyl-10-amino CPT-   (20S)-7-(tert-butyldimethylsilyl)-10-hydroxy CPT-   (20S)-7-[(2-trimethylsilyl)ethyl)] CPT (Karentican)-   (20S)-7-[(4-fluorophenoxy)acetyloxymethyl] CPT-   (20S)-7-[(4-methoxyphenoxy)acetyloxymethyl] CPT-   (20S)-7-[(4-cyano-3-fluorophenoxy)acetyloxymethyl] CPT-   (20S)-7-[(3,4,5-trimethoxyphenyl)acetyloxymethyl] CPT-   (20S)-10-[(4-cyano-3-fluorophenoxy)acetyloxy] CPT-   (20S)-10-[(3,4,5-trimethoxyphenyl)acetyloxy] CPT-   (20S)-7-(4-methylpiperazinomethylene)-10,11-ethylenedioxy CPT    (Exatecan)-   (20S)-7-[2-(N-isopropylamino)ethyl] CPT (Belotecan)-   (20S)-[5(RS)-(2-hydroxyethoxy)] CPT-   (20S)-7-ethyl-9-allyl-10-hydroxy CPT (29)-   (20S)-7-ethyl-9-allyl-10-methoxy CPT (29)-   (20S)-7-ethyl-9-propyl-10-hydroxy CPT (29)-   (20S)-7-ethyl-9-propyl-10-methoxy CPT (29)-   (20S)-7,9-diethyl-10-hydroxy CPT (29)-   (20S)-7,9-diethyl-10-methoxy CPT (29)-   (20S)-10-(substituted quaternary ammonium salts) CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl CPT-   (20S)-7-(2-hydroxyethylamino)methyl CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10,11-methylenedioxy    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10,11-methylenedioxy    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10,11-methylenedioxy CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-amino CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-amino CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-amino CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-nitro CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-nitro CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-nitro CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10-hydroxy CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10-hydroxy CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10-hydroxy CPT; and the like.

Example 4

To a solution of (+)TAPA 3a (1.9 g 4.31 mmol), camptothecin (1.0 g, 2.87mmol), Hobt (426 mg, 3.16 mmol) and DIC (0.89 mL, 5.74 mmol) in any DCM(52 mL) was added a solution of DMAP (140 mg, 1.15 mmol) in any DCM (5mL). After 1 hr at rt, DIC (0.89 mL, 5.74 mmol) and (+)-TAPA 3a (0.67 g,1.43 mmol) were added. The reaction was stirred at rt overnight. Themixture was diluted with DCM (300 mL) and washed with 1N HCl (2×150 mL),saturated aq NaHCO₃ solution (2×150 mL), dried over Na₂SO₄, treated withactivated carbon and filtered. The solvent was evaporated and theremaining residue was purified by silica gel column with 50-80%EtOAc:Hexanes to give 1.85 g of 13 as a yellow solid (83%). ¹H NMR(CDCl₃): δ 9.44 (s, 1H, tetranitrofluorenone), 8.80 (s, 1H,tetranitrofluorenone), 8.52 (s, 1H, tetranitrofluorenone), 8.33 (s, 2H,Ar), 7.91 (d, 1H, J=7.7 Hz, Ar), 7.8-7.65 (m, 2H, Ar), 7.43 (m, 1H, Ar),7.17 (s, 1H), 5.72 (d, 1H, J=17.7 Hz, —C—CH₂—O—C(O)—), 5.55-5.44 (m, 2H,—C—CH₂—O—C(O)— and O—C(O)—CH(Me)-O—), 5.28 (s, 2H, —C—CH₂—N—), 2.35 (dm,2H, J=7.2 Hz, CH₂-Me), 1.83 (d, 3H, J=7.2 Hz, —CH(CH₃)), 0.97 (t, 3H,J=7.2 Hz, CH₃); ¹³C NMR (CDCl₃): δ 168.98, 166.94, 157.36, 152.05,148.97, 148.39, 148.14, 147.47, 146.43, 146.34, 144.80, 140.75, 133.99,133.58, 132.19, 131.64, 131.19, 129.02, 128.80, 128.48, 128.16, 127.19,122.43, 121.18, 121.12, 120.53, 96.15, 81.11, 67.67, 53.80, 50.43,32.39, 17.24, 7.91; M.p. 210-213° C. (dec), ESIMS: calcd for C₃₆H₂₃N₇O₁₄[M+H]⁺ 778.13, found 778.0.

Example 5

To a solution of (+)TAPA 3a (1.43 g, 3.19 mmol), irinotecan (1.25 g,2.13 mmol), Hobt (316 mg, 2.34 mmol) and DCC (1.33 g, 6.38 mmol) in anyDCM (30 mL) was added a solution of DMAP (78 mg, 0.64 mmol) in any DCM(12 mL). After 1 hr at rt, DCC (1.33 g, 6.38 mmol) was added. Thereaction was stirred at rt overnight. The mixture was filtered, dilutedwith DCM (25 mL) and washed with 1N HCl (2×25 mL), saturated aq NaHCO₃solution (2×25 mL), dried over Na₂SO₄, treated with activated carbon andfiltered. The solvent was evaporated and the remaining residue waspurified by silica gel column with 5-10% MeOH:DCM and concentrated.Added 2N HCl in Et₂O (10 mL) and the mixture was decanted into 1:1EtOAc:Et₂O (50 mL), filtered and dried to give 1.15 g of 14 ashydrochloride salt (51%). ¹H NMR (CDCl₃): δ 9.43 (s, 1H,tetranitrofluorenone), 8.79 (s, 1H, tetranitrofluorenone), 8.49 (s, 1H,tetranitrofluorenone), 8.36 (s, 2H, Ar), 7.81 (s, 1H, Ar), 7.66 (d, 1H,J=9.3 Hz, Ar), 7.49 (s, 1H, J=9.3 Hz, Ar), 7.08 (s, 1H), 5.71 (d, 1H,17.4 Hz, —C—CH₂—O—C(O)—), 5.53-5.43 (m, 2H, —C—CH₂—O—C(O)— andO—C(O)—CH(Me)-O—), 5.24 (s, 2H, —C—CH₂—N—), 4.48 (d, 2H, J=12.3 Hz),4.36 (d, 2H, J=12.3 Hz), 3.20-2.50 (m, 7H), 2.60 (dm, 2H, J=7.8 Hz,CH₂), 2.15-1.50 (m, 12H), 1.40 (t, 3H, J=7.5 Hz, CH₃), 0.95 (t, 3H,J=7.5 Hz, CH₃); M.p. 210-215 (dec); ESIMS: calcd for C₄₉H₄₅N₉O₁₆ [M+H]⁺1016.30, found 1016.5.

Example 6

To a solution of TNF-ethanoic acid 4 (1.43 g, 3.19 mmol), irinotecan(1.25 g, 2.13 mmol), Hobt (316 mg, 2.34 mmol) and DCC (1.33 g, 6.38mmol) in any DCM (30 mL) was added a solution of DMAP (78 mg, 0.64 mmol)in any DCM (12 mL). After 1 hr at rt, DCC (1.33 g, 6.38 mmol) was added.The reaction was stirred at rt overnight. The mixture was filtered anddiluted with DCM (25 mL) and washed with 1N HCl (2×25 mL), saturated aqNaHCO₃ solution (2×25 mL), dried over Na₂SO₄, treated with activatedcarbon and filtered. The solvent was evaporated and the remainingresidue was purified by silica gel column with 5-10% MeOH:DCM andconcentrated. Added 2N HCl in Et₂O (10 mL) and the mixture was decantedinto 1:1 EtOAc:Et₂O (50 mL), filtered and dried to give 1.15 g of 15 ashydrochloride salt, yellow in color (51%). ¹H NMR (CDCl₃): δ 9.46 (s,1H, tetranitrofluorenone), 8.89 (s, 1H, tetranitrofluorenone), 8.61 (s,1H, tetranitrofluorenone), 8.53 (s, 1H, tetranitrofluorenone), 7.85-7.77(m, 2H, Ar), 7.48 (d, 1H, Ar), 7.14 (s, 1H), 5.62-5.32 (m, 4H,—C—CH₂—O—C(O)— and O—C(O)—CH₂—O—N—), 5.23 (s, 2H, —C—CH₂—N—), 4.48 (d,2H, J=12.3 Hz), 4.36 (d, 2H, J=12.3 Hz), 3.60-2.80 (m, 7H), 2.60-2.20(m, 4H), 2.18-1.80 (m, 8H), 1.36 (t, 3H, J=7.5 Hz, CH₃), 0.98 (t, 3H,J=7.5 Hz, CH₃); M.p. 210-215 (dec); ESIMS: calcd for C₄₈H₄₃N₉O₁₆ [M+H]⁺1002.28, found 1002.5.

Example 7

The 20-O-(TNF-ethanoyl)-Boc-10H-CPT ester 8 (5.3 g, 6.02 mmol) wasdissolved in TFA (60 mL). After stirring at rt for 1 hr,bis-(dimethylamine)-methane (30 mL) was added slowly. The mixture wasstirred at rt for 45 min and the crude product was precipitated byaddition to water. Filtered and the precipitate was dissolved in DCM(300 mL), washed with saturated NaHCO₃ solution (3×200 mL, the solutionturned red), dried over Na₂SO₄, filtered and the solvent was removed.The dark red solid was dissolved in MeOH (100 mL) and added 30 mL of 2MHCl in Et₂O. The solvent was evaporated and the residue was purified bysilica gel column with 5-20% MeOH:DCM to afford 3.32 g of 16 ashydrochloride salt (63%). ¹H NMR (1:1 CDCl₃:CD₃OD): δ 9.47 (s, 1H,tetranitrofluorenone), 8.94 (s, 2H, tetranitrofluorenone and Ar), 8.70(s, 1H, tetranitrofluorenone), 8.63 (s, 1H, tetranitrofluorenone), 8.04(d, 1H, J=9.3 Hz, Ar), 7.59 (d, 1H, J=9.3 Hz, Ar), 7.36 (s, 1H), 5.66(d, 1H, J=17.1 Hz, —C—CH₂—O—C(O)—), 5.55-5.40 (m, 3H, —C—CH₂—O—C(O)— andO—C(O)—CH₂—O—N—), 5.37 (s, 2H, —C—CH₂—N—), 4.81 (s, 2H, —CH₂—N(Me)₂),2.99 (s, 3H, N(CH₃)₂), 2.95 (s, 3H, N(CH₃)₂), 2.50 (dm, 2H, J=6.9 Hz,CH₂-Me), 1.03 (t, 3H, J=6.9 Hz, CH₃); M.p. 210-215° C. (dec); ESIMS:calcd for C₃₈H₂₈N₈O₁₅ [M+H]⁺ 837.17, found 837.4.

Example 8

To a solution of (−)TAPA 3b (960 mg 2.15 mmol), camptothecin (0.5 g,1.44 mmol), Hobt (213 mg, 1.44 mmol) and DCC (0.89 g, 4.3 mmol) in anyDCM (25 mL) was added a solution of DMAP (70 mg, 0.57 mmol) in any DCM(3 mL). After 1 hr at rt, DCC (0.89 g, 4.3 mmol) and (−)TAPA 3b (320 mg,0.72 mmol) were added. The reaction was stirred at rt overnight. Themixture was filtered, diluted with DCM (75 mL) and washed with 1N HCl(2×100 mL), saturated aq NaHCO₃ solution (2×100 mL), dried over Na₂SO₄,treated with activated carbon and filtered. The solvent was evaporatedand the remaining residue was purified by silica gel column with 50-80%EtOAc:Hexanes to give 0.97 g of 17 as yellow solid (87%). ¹H NMR(CDCl₃): δ 9.54 (s, 1H, tetranitrofluorenone), 9.01 (s, 1H,tetranitrofluorenone), 8.43 (s, 1H, tetranitrofluorenone), 8.33 (s, 2H,Ar), 7.92 (d, 1H, J=7.8 Hz, Ar), 7.80-7.63 (m, 3H, Ar), 7.08 (s, 1H),5.72 (d, 1H, J=17.7 Hz, —C—CH₂—O—C(O)—), 5.56-5.44 (m, 2H,—C—CH₂—O—C(O)— and O—C(O)—CH(Me)-O—), 5.29 (s, 2H, —C—CH₂—N—), 2.35 (dm,2H, J=7.2 Hz, CH₂-Me), 1.97 (d, 3H, J=6.9 Hz, —CH(CH₃)), 0.99 (t, 3H,J=7.2 Hz, CH₃); ESIMS: calcd for C₃₆H₂₃N₇O₁₄ [M+H]⁺ 778.13, found 778.0.

Example 9

To a solution of (−)TAPA 3b (230 mg, 0.51 mmol), irinotecan (200 mg,0.34 mmol), Hobt (51 mg, 0.38 mmol) and DIC (160 μL, 1.02 mmol) in anyDCM (6 mL) was added a solution of DMAP (16 mg, 0.14 mmol) in any DCM (1mL). After 1 hr at rt, DIC (160 μL, 1.02 mmol) and (−)TAPA (75 mg, 0.17mmol) were added. The reaction was stirred at rt overnight. The mixturewas diluted with DCM (50 mL) and washed with 1N HCl (2×25 mL), saturatedaq NaHCO₃ solution (2×25 mL), dried over Na₂SO₄, treated with activatedcarbon and filtered. The solvent was evaporated and the remainingresidue was purified by silica gel column with 5-10% MeOH:DCM andconcentrated. Added 2N HCl in Et₂O (5 mL) and the mixture was decantedinto 1:1 EtOAc:Et₂O (50 mL), filtered and dried to give 255 mg of 18 ashydrochloride salt (71%). ¹H NMR (CDCl₃): δ 9.52 (s, 1H,tetranitrofluorenone), 8.99 (s, 1H, tetranitrofluorenone), 8.36 (s, 1H,Ar), 8.20 (s, 1H, Ar), 8.00 (s, 1H, Ar), 7.81-7.45 (m, 3H, Ar), 7.01 (s,1H), 5.71 (d, 1H, 17.4 Hz, —C—CH₂—O—C(O)—), 5.53-5.43 (m, 2H,—C—CH₂—O—C(O)— and O—C(O)—CH(Me)-O—), 5.24 (s, 2H, —C—CH₂—N—), 4.48 (d,2H, J=12.3 Hz), 4.36 (d, 2H, J=12.3 Hz), 3.20-2.50 (m, 7H), 2.60 (dm,2H, J=7.8 Hz, CH₂), 2.15-1.50 (m, 12H), 1.40 (t, 3H, J=7.5 Hz, CH₃),0.95 (t, 3H, J=7.5 Hz, CH₃); ESIMS: calcd for C₄₉H₄₅N₉O₁₆ [M+H]⁺1016.30, found 1016.5.

Example 10

To a solution of 9F-ethanoic acid 5 (146 mg 0.57 mmol), camptothecin(100 mg, 0.29 mmol) and DIC (133 μL, 0.86 mmol) in any DCM (6 mL) wasadded DMAP (14 mg, 0.11 mmol). After 22 hr at rt, DIC (133 μL, 0.86mmol) and 9F-ethanoic acid 9 (70 mg, 0.29 mmol) were added. The reactionwas stirred at rt overnight, diluted with DCM (50 mL) and washed with 1NHCl (2×25 mL), saturated aq NaHCO₃ solution (2×25 mL), dried over Na₂SO₄and filtered. The solvent was evaporated and the remaining residue waspurified by silica gel column with 30-100% EtOAc:Hexanes to give 53 mgof 19 as light yellow solid (32%). ¹H NMR (1:5 acetone-d6:CDCl₃): δ 8.32(s, 1H, Ar), 8.23 (d, 1H, J=7.5 Hz, Ar), 8.16 (d, 1H, J=8.4 Hz, Ar),7.92-7.60 (m, 4H, Ar), 7.47 (d, 1H, J=7.8 Hz, Ar), 7.38-7.20 (m, 4H, Ar,═CH—), 7.08 (t, 1H, J=7.8 Hz, Ar), 6.65 (t, 1H, J=7.5 Hz, Ar), 5.61 (d,1H, J=17.4 Hz, —C—CH₂—O—C(O)—), 5.31 (d, 1H, J=17.4 Hz, —C—CH₂—O—C(O)—),5.18 (s, 2H, —C—CH₂—N—), 5.05 (dd, 2H, J=16.5 Hz, 24.9 Hz,O—C(O)—CH₂—O—), 2.09 (m, 2H, J=8.4 Hz, CH₂-Me), 0.88 (t, 3H, J=8.4 Hz,CH₃); ESIMS: calcd for C₃₅H₂₅N₃O₆ [M+H]⁺ 584.17, found 584.3, 1167.7(dimer).

By substituting other camptothecin analogs CPT in this example othercompounds of this invention are prepared. Other camptothecin analogsinclude the following:

-   (20S)-7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)-CPT    (AKA-irinotecan);-   (20S)-9-nitro CPT;-   (20S)-7-chloro-n-propyldimethylsilyl CPT;-   (20S)-10-hydroxy-7-chloro-n-propyldimethylsilyl CPT;-   (20S)-10-acetoxy-7-chloro-n-propyldimethylsilyl CPT;-   (20S)-7-tert-butyldimethylsilyl CPT;-   (20S)-10-hydroxy-7-tert-butyldimethylsilyl CPT;-   (20S)-10-acetoxy-7-tert-butyldimethylsilyl CPT;-   (20S)-9-hydroxy CPT;-   (20S)-9-amino CPT;-   (20S)-10-amino CPT;-   (20S)-9-amino-10-hydroxy CPT;-   (20S)-9-methylamino CPT;-   (20S)-9-chloro CPT;-   (20S)-9-fluoro CPT;-   (20S)-9-piperidino CPT;-   (20S)-9-dimethylaminomethyl-10-hydroxy CPT (3)-AKA topotecan);-   (20S)-9-morpholinomethyl CPT;-   (20S)-9,10-dichloro CPT;-   (20S)-10-bromo CPT;-   (20S)-10-chloro CPT;-   (20S)-10-methyl CPT;-   (20S)-10-fluoro CPT;-   (20S)-10-nitro CPT;-   (20S)-10,11-methylenedioxy CPT;-   (20S)-10-formyl CPT;-   (20S)-10-nonylcarbonyloxy CPT;-   (20S)-10-undecylcarbonyloxy CPT;-   (20S)-10-heptadecylcarbonyloxy CPT;-   (20S)-10-nonadecylcarbonyloxy CPT;-   (20S)-9-nitro-10,11-methylenedioxy CPT;-   (20S)-9-(4-methylpiperazinylmethyl)-10-hydroxy (CPT);-   (20S)-9-[4-(1-piperidino)-1-piperidinomethyl]-10-hydroxy CPT;-   (20S)-9-methyl-10,11-methylenedioxy CPT;-   (20S)-9-chloro-10,11-methylenedioxy CPT;-   (20S)-9-cyano-10,11-methylenedioxy CPT;-   (20S)-9-acetoxy-10,11-methylenedioxy CPT;-   (20S)-9-acetylamino-10,11-methylenedioxy CPT;-   (20S)-9-aminomethyl-10-hydroxy CPT;-   (20S)-9-ethoxymethyl-10-hydroxy CPT;-   (20S)-9-methylaminomethyl-10-hydroxy CPT;-   (20S)-9-n-propylaminomethyl-10-hydroxy CPT;-   (20S)-9-dimethylaminomethyl-10-hydroxy CPT;-   (20S)-9-cyclohexylaminomethyl-10-hydroxy CPT;-   (20S)-9-(2-hydroxyethyl)aminomethyl-10-hydroxy CPT;-   (20S)-9-(trimethylammonio)methyl-10-hydroxy CPT, methanesulfonate;-   (20S)-9-morpholinomethyl-10-hydroxy CPT;-   (20S)-5-(2-hydroxyethoxy) CPT-   (20S)-9-cyanomethyl-10-hydroxy CPT;-   (20S)-CPT-7-aldehyde;-   (20S)-10-methoxy CPT-7-aldehyde;-   (20S)-7-acetoxymethyl CPT;-   (20S)-7-acetoxymethyl-10-methyl CPT;-   (20S)-7-cyano-10-methoxy CPT;-   (20S)-7-cyano CPT;-   (20S)-7-formylethenyl CPT;-   (20S)-7-ethoxycarbonylethenyl CPT;-   (20S)-7-cyanoethenyl CPT;-   (20S)-7-(2,2-dicyanoethenyl) CPT;-   (20S)-7-(2-cyano-2-ethoxycarbonyl)ethenyl CPT;-   (20S)-7-ethoxycarbonylethyl CPT;-   (20S)-7-ethyl CPT;-   (20S)-7-n-propyl CPT;-   (20S)-7-acetoxymethyl CPT;-   (20S)-7-n-propylcarbonyloxymethyl CPT;-   (20S)-7-ethoxycarbonyl CPT;-   (20S)-7-ethyl-10-hydroxy CPT;-   (20S)-7-ethyl-10-acetyloxy CPT;-   (20S)-7-methyl-10-aminocarbonyloxy CPT;-   (20S)-7-n-propyl-10-piperidinocazbonyloxy CPT;-   (20S)-7-ethyl-10-(2-dimethylamino)ethyl CPT; and-   (20S)-7-ethyl-10-carbamoyloxy derivatives of CPT such as-   (20S)-7-ethyl-10-[4(1-piperidino)-piperidino carbonyloxy CPT;-   (20S)-7-ethyl-10-(1-piperazine)carbonyloxy CPT;-   (20S)-7-ethyl-10-(4-1-propylaminocarbonylmethylpiperazine)carbonyloxy    CPT;-   (20S)-7-ethyl-10-[4(1-pyrrolidinyl)piperazine]carbonyloxy CPT;-   (20S)-7-ethyl-10-[(4-(dimethylamino)-1-piperidino]carbonyloxy CPT;-   (20S)-7-ethyl-10-[4-(di-n-propylamino)-1-piperidinol]carbonyloxy    CPT;-   (20S)-7-ethyl-10-[(4-(di-n-butylamino)-1-piperidino]carbonyloxy CPT;-   (20S)-7-ethyl-10-[4-(1-pyrrolidino)-1-piperidino)]carbonyloxy CPT;-   (20S)-7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy CPT;-   (20S)-7-ethyl-10-[N-methyl-N-2-(dimethylamino)ethylamino]carbonyloxy    CPT-   (20S)-7-(tert-butyldimethylsilyl)CPT-   (20S)-7-(tert-butoxyiminomethyl) CPT (Gimatecan)-   (20S)-7-butyl-10,11-methylenedioxy CPT-   (20S)-7-bromomethyl-10-hydroxy CPT-   (20S)-7-butyl-10-amino CPT-   (20S)-7-(tert-butyldimethylsilyl)-10-hydroxy CPT-   (20S)-7-[(2-trimethylsilyl)ethyl)] CPT (Karentican)-   (20S)-7-[(4-fluorophenoxy)acetyloxymethyl] CPT-   (20S)-7-[(4-methoxyphenoxy)acetyloxymethyl] CPT-   (20S)-7-[(4-cyano-3-fluorophenoxy)acetyloxymethyl] CPT-   (20S)-7-[(3,4,5-trimethoxyphenyl)acetyloxymethyl] CPT-   (20S)-10-[(4-cyano-3-fluorophenoxy)acetyloxy] CPT-   (20S)-10-[(3,4,5-trimethoxyphenyl)acetyloxy] CPT-   (20S)-7-(4-methylpiperazinomethylene)-10,11-ethylenedioxy CPT    (Exatecan)-   (20S)-7-[2-(N-isopropylamino)ethyl] CPT (Belotecan)-   (20S)-[5(RS)-(2-hydroxyethoxy)] CPT-   (20S)-7-ethyl-9-allyl-10-hydroxy CPT (29)-   (20S)-7-ethyl-9-allyl-10-methoxy CPT (29)-   (20S)-7-ethyl-9-propyl-10-hydroxy CPT (29)-   (20S)-7-ethyl-9-propyl-10-methoxy CPT (29)-   (20S)-7,9-diethyl-10-hydroxy CPT (29)-   (20S)-7,9-diethyl-10-methoxy CPT (29)-   (20S)-10-(substituted quaternary ammonium salts) CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl CPT-   (20S)-7-(2-hydroxyethylamino)methyl CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10,11-methylenedioxy    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10,11-methylenedioxy    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10,11-methylenedioxy CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy)    CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-dimethylaminomethyl-10-hydroxy    CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-amino CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-amino CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-amino CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-9-nitro CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-9-nitro CPT-   (20S)-7-(2-hydroxyethylamino)methyl-9-nitro CPT-   (20S)-7-(tris(hydroxymethyl)methylamino)methyl-10-hydroxy CPT-   (20S)-7-(bis(hydroxymethyl)methylamino)methyl-10-hydroxy CPT-   (20S)-7-(2-hydroxyethylamino)methyl-10-hydroxy CPT; and the like.

Example 11

The 20-O-[(+)TAPA]-Boc-10H-CPT ester 9 (500 mg, 0.538 mmol) wasdissolved in TFA (5.4 mL). After stirring at rt for 1 hr, the reactionmixture was added to water and the precipitate was filtered, dried andredissolved in DCM. The solution was dried over Na₂SO₄, filtered and thesolvent was removed. The remaining residue was purified by silica gelcolumn with 50-100% EtOAc:Hexanes to give 370 mg of 20 as yellow solid(89%). ¹H NMR (1:1 Acetone-d6:CDCl₃) δ 9.37 (s, 1H, Ar), 8.72 (s, 1H,Ar), 8.41 (s, 1H, Ar), 8.23 (s, 1H, Ar), 8.05 (s, 1H, Ar), 7.45 (d, 1H,J=9.3 Hz, Ar), 7.32 (d, 1H, J=9.3 Hz, Ar), 7.16 (s, 1H, Ar), 6.99 (s,1H, ═CH—), 5.63 (d, 1H, J=17.4 Hz, —C—CH₂—O—C(O)—), 5.50-5.37 (m, 2H,—C—CH₂—O—C(O)— and O—C(O)—CH(Me)-O—), 5.15 (s, 2H, —C—CH₂—N—), 2.23 (dm,2H, J=7.5 Hz, CH₂-Me), 1.74 (d, 3H, J=7.2 Hz, CH₃), 0.87 (t, 3H, J=7.5Hz, CH₃); ¹³C NMR (2:1 CDCl₃:acetone-d6): δ 157.12, 148.98, 147.61,146.28, 144.40, 134.01, 130.37, 129.85, 129.49, 129.27, 127.22, 123.63,122.87, 122.59, 121.11, 120.45, 120.26, 109.29, 95.13, 80.81, 77.22,67.63, 50.33, 32.21, 17.04, 7.73; M.p. 210-215° C. (dec); ESIMS: calcdfor C₃₆H₂₃N₇O₁₅ [M+H]⁺ 794.13, found 794.3.

Example 12

To a solution of 9F-propionic acid 6 (1.7 g 6.36 mmol), Boc-10H-CPT 7 (2g, 4.3 mmol) and DIC (2 mL, 12.9 mmol) in any DCM (86 mL) was added DMAP(210 mg, 1.72 mmol). The reaction was stirred at rt for 1 hr, washedwith saturated NaHCO₃ solution (1×50 mL), 1N HCl (2×50 mL), dried overNa₂SO₄ and the solvent was removed. The remaining residue was dissolvedin 25 mL of DCM, precipitated with 200 mL of MeOH and filtered to give3.05 g of 21 as a light yellow solid (99%). NMR (CDCl₃) δ 8.28 (m, 1H,Ar), 8.14 (d, 1H, J=9.3 Hz, Ar), 7.80-7.20 (m, 8H), 6.98 (t, 1H, J=7.2Hz, Ar), 6.30 (t, 1H, J=7.5 Hz, Ar), 5.70 (d, 1H, J=17.4 Hz,—C—CH₂—O—C(O)—), 5.40 (d, 1H, J=17.4 Hz, —C—CH₂—O—C(O)—), 5.30-5.20 (m,3H, —O—C(O)—CH(Me)-O—), and —C—CH₂—N—), 2.24 (dm, 2H, J=7.8 Hz,—CH₂-Me), 1.80 (d, 3H, J=7.2 Hz, —CH₃), 1.64 (s, 9H, 3 CH₃, t-Bu), 1.01(t, 3H, J=7.8 Hz, —CH₃); ESIMS: calcd for C₄₁H₃₅N₃O₉ [M+H] 714.24, found714.4, 1427.4 (dimer).

Example 13 In Vitro Chemoradiosensitization

Chemoradiosensitizing effects of compound 13 on human cancer cells wereevaluated at a dose of 5 nM. DMS-114 small lung cancer cells were platedon petri dishes in triplicates were allowed to attach. The cells weresubjected to 2 h drug exposures at 37° C. and then irradiated withX-rays at the doses indicated in Table 2. After irradiation, cells wererinsed with HBSS (Hank's balanced salt solution), and covered with freshmedia. Cells were cultured for 8-9 days in a 37° C. incubator. Theresulting cell colonies were stained and counted. Prior exposure tocompound 13 significantly increased the radiosensitivity of the cancercell (Table 2). Other compounds of this invention can similarly beevaluated in accordance with this method.

TABLE 2 In vitro chemoradiosensitization Survival (%) Radiation +Radiation Radiation compound Dose (Gy) alone 13 0 100 100 2 98 44 4 9623 8 72 3

Example 14 In Vivo Chemoradiosensitization

To determine whether the pronounced effects of compound 13 in tissueculture could be duplicated in solid tumors, in vivochemoradiosensitization studies were performed on C3H/HeN mice bearingMTG-B mouse mammary adenocarcinoma tumors. Prior to treatment, the tumorgrew exponentially following implantation into the flanks of the miceand reached a diameter of 8 mm (268.08 cu. mm) by day 7 to 10. The micewere injected i.p. with compound 13 at MTD using a single injection andthen irradiated with a radiation dose of 22 Gy 24 h after the injection.Control groups of mice bearing 8 mm diameter tumors were treated withvehicle alone, or radiation alone, or drug alone. After treatment, tumorsizes were measured by caliper every day. Daily measurement of the tumordiameters (d1, d2) in two orthogonal directions were used to calculatethe tumor volume (tumor volume=π/6 {(d1+d2)/2}³) using the approximationthat the tumors were spherical (results shown in FIG. 1). The values oftime (days) required to grow the tumor to twice their initial size aftervarious treatments were calculated as tumor doubling time (TDT) (±SE)for evaluating the treatment effects. Survival times and curativeeffects after treatment were also be observed and recorded. Othercompounds of this invention can similarly be evaluated in accordancewith this method.

TABLE 3 In vivo Chemoradiosensitization TDT Survival regimen (days)(days) control 1 7 Radiation alone 2 15 compound 13 12 24 alone compound13 33 90 plus radiation

Example 15 Chemotherapeutic Activity of Compound 13

Chemotherapeutic effects of compound 13 on human prostate cancer cells(PC-3 and DU-145) were evaluated at dose concentrations between 0 and 10nM. Cells plated on Petri dishes in triplicates were allowed to attach,then cells were subjected to 24 hr drug exposure at 37° C. The cellswere then rinsed with HBSS ((Hank's balanced salt solution) and coveredwith fresh media. Cells were cultured for 8-9 days in a 37° C.incubator. The resulting cell colonies were stained and counted. Resultsare presented in Table 4.

TABLE 4 Chemotherapeutic Activity of compound 13 PC-3 DU-145 Drug conc.Cells Cells (nM) % Survival % Survival 0 100 100 1 98 82 5 52 43 10 10 5

Chemotherapeutic effects of compound 13 on human breast cancer cells(MCF7) were evaluated at dose concentrations between 0 and 10 nM. Cellsplated on Petri dishes in triplicates were allowed to attach, then cellswere subjected to 72 hr drug exposure at 37° C. The cells were thenrinsed with HBSS ((Hank's balanced salt solution) and covered with freshmedia. Cells were cultured for 8-9 days in a 37° C. incubator. Theresulting cell colonies were stained and counted. Results are presentedin FIG. 2. Other compounds of this invention can similarly be evaluatedin accordance with this method.

Example 16 Decreased toxicity of Compound 13

Drugs were dissolved in cremophor:alcohol (1:1) and diluted in saline toa 5% cremophor, 5% alcohol, 90% saline for i.p. injection.

Acute toxicities of a compound of this invention, compound 13,topotecan, CPT and cisplatin were evaluated on C3H/HeN mice (female, 6-8week old, body weight 18-20 g). The MTD40 (maximum tolerated dose at day40) values were determined. In the consecutive type studies, 6 mice weredosed at moderate doses of 10, 70, or 106.98, or 141.47, or 187.1 mg/kg.If no severe and irreversible toxicity (euthanasia is required) occurredat these doses, additional 6 animals were initiated at a dose which is1.3225-1.5283 times higher than the previous non-toxic doses. Sequentialdosages (261.94, or 366.72, or 500 mg/kg) were increased until severeand irreversible toxicity (whereby euthanasia is required) occurs. Ifsevere and irreversible toxicity was observed at these doses, the drugdoses (50, or 30 mg/kg) were reduced. The result of this exercise wastwo dosages, one apparently nonlethal and the other lethal if severe andirreversible toxicity occurred and euthanasia was required. Six micewere dosed at each dosage. If no severe and irreversible toxicityoccurred at the lower dosage and at least one with severe andirreversible toxicity at the higher dose, then the lower dose wasconsidered to the MTD. These new camptothecin analogs were administeredto C3H/HeN mice by i.p. injection. Drug toxicity was evaluated on mice,checked daily for 45 days. The toxicity parameters reported were theMTD40. The MTD is defined as the highest dose causing no severeirreversible toxicity in one treatment group, but at least one animalexhibiting severe and irreversible toxicity and being euthanized at nexthigher dose. Results are provided in FIG. 3. Other compounds of thisinvention can similarly be evaluated in accordance with this method.

Example 17 In Vitro Chemoradiosensitization

Chemoradiosensitizing effects of compound 13, compound 10, and compound20 on human cancer cells were evaluated at a dose of 5 nM. PC-3 humanprostate cancer cells were plated on petri dishes in triplicates wereallowed to attach. The cells were subjected to 2 h drug exposures at 37°C. and then irradiated with X-rays at the doses indicated in Table 5.After irradiation, cells were rinsed with HBSS (Hank's balanced saltsolution), and covered with fresh media. Cells were cultured for 8-9days in a 37° C. incubator. The resulting cell colonies were stained andcounted. Prior exposure to compound 13, compound 10, and compound 20significantly increased the radiosensitivity of the cancer cell (Table5). Other compounds of this invention can similarly be evaluated inaccordance with this method.

TABLE 5 In vitro chemoradiosensitization Radiation Survival (%) DoseRadiation Radiation + Radiation Radiation + Radiation Radiation + (Gy)alone compound 13 alone compound 10 alone compound 20 0 100 100 100 100100 100 1 97 83 98 90 98 82 2 90 60 87 66 88 65 4 50 22 50 21 47 22

Example 18 Chemotherapeutic Activity of CPT analogs Cell ColonyFormation Assay

Four hundred cells (HCT116: human colon cancer cell line) or fivehundred cells (VM46: taxol-resistant, overexpressing multi-drugresistant gene, sub-line of HCT-116) (PC-3: human prostate cancer cellline) were plated in 60 mm Petri dishes containing 2.7 mL of medium(modified McCoy's 5a medium containing 10% fetal bovine serum and 100units/ml penicillin and 100 μg/ml streptomycin). The cells wereincubated in a CO₂ incubator at 37° C. for 5 hours for attachment to thebottom of Petri dishes. Drugs were made up fresh in medium at ten timesthe final concentration, and then 0.3 ml of this stock solution wasadded to the 2.7 mL of medium containing 5% bovine calf serum (BCS) inthe dish. The cells were then incubated with drugs for 72 hours at 37°C. At the end of incubation the drug-containing media were decanted, thedishes were rinsed with 4 ml of Hank's Balance Salt Solution (HBSS), 5ml of fresh medium containing 15% BCS was added, and the dishes werereturned to the incubator for colony formation. The cell coloniesstained with methylene blue (0.5% in ethanol) were counted using colonycounter after incubation for 8 days for HCT116 cells and PC-3 cells and9 days for VM46 cells, respectively. Cell survival was calculated andthe values of IC50 (the drug concentration producing 50% inhibition ofcolony formation) were determined for each tested compound. Results areprovided in Table 6. Other compounds of this invention can similarly beevaluated in accordance with this method.

TABLE 6 Chemotherapeutic Activity of CPT analogs IC50 (nM) Compound #HCT116 PC-3 VM46 13 3.2 5.0 3.0 14 no effect — no effect 10 16.4  — 11  15 no effect — no effect 16 8.6 — 6.7 17 4.0 6.0 3.0 18 no effect — noeffect 12 7.7 — 5.7 19 3.0 — 0.6 20 3.3 6.0 1.5  8 3.0 — 0.6 21 3.0 —0.6 Topotecan 10.3  no effect 10.6 

Several CPT analogs tested above showed in vitro chemotherapeuticactivity against human colon cancer cell line (HCT116:), sub-line ofHCT116 (VM46) and human prostate cancer cell line (PC-3). The threecompounds that did not display any in vitro chemotherapeutic effect,namely compound 14, compound 15, and compound 18, are analogs ofIrinotecan: a semisynthetic camptothecin derivative introduced in the1980's. Irinotecan is a prodrug metabolized by carboxylesterases to anactive metabolite 7-ethyl-10-hydroxy-camptothecin (SN38) which thenexerts its cytotoxic effect (Ando Y. al. N Engl Med 2002;346(18):1414-1415). Accordingly, Irinotecan derivatives can be expectednot to display any in vitro chemotherapeutic activity but display onlyin vivo activity after getting metabolized in the body, which isconsistent with the lack of in vitro activity seen for the 3 Irinotecananalogs mentioned above.

1. A method of sensitizing a subject's tumor cells to radiation, whichmethod comprises a) administering to the subject in need thereof acamptothecin-based compound comprising one or more radiosensitizingelectron-affinic groups and b) exposing the tumor cells in the subjectto a unit dose of radiation.
 2. The method of claim 1, wherein at leastone of the radiosensitizing electron-affinic groups is anitro-substituted carbocyclic or a nitro-substituted heterocyclic moietythat is attached to the C5, C7, C9, C10, C11, C12 or C20 position ofcamptothecin.
 3. The method of claim 2, wherein the carbocyclic orheterocyclic moiety at the C7, C9, C10, C11, C12 or C20 position ofcamptothecin is aromatic.
 4. The method of claim 2, wherein thecarbocyclic or heterocyclic moiety is(+)-2-(2,4,5,7-tetranitro-9-fluorenylideneaminooxy)-propionic acid(TAPA).
 5. The method of claim 2, wherein the carbocyclic orheterocyclic moiety is(−)-2-(2,4,5,7-tetranitro-9-fluorenylideneaminooxy)-propionic acid(TAPA).
 6. The method of claim 2, wherein the carbocyclic orheterocyclic moiety is2-(2,4,5,7-tetranitro-9-fluorenylideneaminooxy)-ethanoic acid(TNF-ethanoic acid).
 7. The method of claim 1, wherein thecamptothecin-based compound is selected from the group consisting of:


8. The method according to claim 1, where steps a) and b) are appliedaccording to a treatment schedule effective to produce a synergisticanti-neoplastic effect.
 9. A method of sensitizing a subject's tumorcells to radiation, which method comprises a) administering to thesubject a compound or a pharmaceutically acceptable salt thereof having

wherein W is alkyl-C(O)—, or R¹Y-L-C(O)—, provided that when W isalkyl-C(O)—, at least one of R², R³, R⁴, R⁵, or R⁶ is nitro; L is a bondor linear alkylene (1-8) group, optionally substituted with lower alkylor substituted lower alkyl, wherein one or two methylene (—CH₂—) unitsof the linear alkylene group is optionally replaced with O, S or NH; Yis ═NO—, —N(H)O—, ═N—, —NR—, O, S, or a bond; R is H, alkyl, orsubstituted alkyl; R¹ is optionally substituted carbocyclic,heterocyclic, or fused 2-, 3-or 4-ring heterocyclic; R² is hydrogen,halo, lower alkyl, lower alkoxy, hydroxy, R^(Q)Y, R^(Q)Y-L-C(O)O—,cyano, nitro, amino, halogenated lower alkyl, halogenated lower alkoxy,hydroxycarbonyl, formyl, lower alkoxycarbonyl, tri lower alkylsilyl,lower alkylcarbonyloxy, lower alkoxycarbonyloxy, sugar, phosphosugar,O-quinone, substituted lower alkyl aminomethyl, loweralkylcarbonylamino, lower alkylcarbonyloxy methyl, optionallysubstituted lower alkylcarbonyloxy methyl, substituted vinyl,1-hydroxy-2-nitroethyl, alkoxycarbonylethyl, aminocarbonyl,alkylcarbonyl, benzoylmethyl, benzylcarbonyloxymethyl, loweralkyliminomethyl or lower alkoxymethyl; R³ is hydrogen, halo, loweralkyl, lower alkoxy, hydroxy, R^(Q)Y-L-C(O)O—, cyano, nitro, amino,halogenated lower alkyl, halogenated lower alkoxy, hydroxycarbonyl,formyl, lower alkoxycarbonyl, lower alkoxycarbonyloxy, sugar,phosphosugar, O-quinone, substituted lower alkyl aminomethyl, CH₂NR⁷R⁸(where each of R⁷ and R⁸ is independently H, alkyl of 1-6 carbons,optionally substituted phenyl, hydroxy lower alkyl, amino lower alkyl,or mono- or dialkylamino lower alkyl, or R⁷ and R⁸ taken together with—N— represent a cyclic amino-), CH₂R⁹ (where R⁹ is lower alkoxy, cyano,amino lower alkoxy, mono- or di-lower alkylamino lower alkoxy, loweralkylthio, amino lower alkylthio, or mono- or di-lower alkylamino loweralkylthio), NR¹⁰R¹¹ (where each of R¹⁰ and R¹¹ is independentlyhydrogen, lower alkyl, phenyl, hydroxy lower alkyl, or amino loweralkyl, or R¹⁰ and R¹¹ taken together with —N— represent a cyclic amino),trialkylsilyl, dialkylamino alkyl, lower alkylcarbonyloxy, or loweralkylcarbonylamino or R³ together with R⁴ is furan, dihydrofuran or1,4-oxazine-2-one; and R⁴ is hydrogen, halo, lower alkyl, lower alkoxy,hydroxy, R^(Q)Y-L-C(O)O—, cyano, nitro, amino, amino lower alkyl,halogenated lower alkyl, halogenated lower alkoxy, hydroxycarbonyl,formyl, lower alkoxycarbonyl, carbamoyloxy, lower alkylcarbonyloxy,lower alkoxycarbonyloxy, sugar, phosphosugar, O-quinone, substitutedlower alkyl aminomethyl, or lower alkylcarbonylamino, or R⁴ togetherwith R³ is furan, dihydrofuran or 1,4-oxazine-2-one, or R⁴ together withR⁵ is methylenedioxy; R⁵ is hydrogen, halo, lower alkyl, lower alkoxy,hydroxy, R^(Q)Y-L-C(O)O—, cyano, nitro, amino, trialkylsilyl,halogenated lower alkyl, halogenated lower alkoxy, hydroxycarbonyl,formyl, lower alkoxycarbonyl, lower alkylcarbonyloxy, loweralkoxycarbonyloxy, sugar, phosphosugar, O-quinone, substituted loweralkyl aminomethyl, or lower alkylcarbonylamino, or R⁵ together with R⁴is methylenedioxy; R⁶ is hydrogen, halo, lower alkyl, lower alkoxy,hydroxy, R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,halogenated lower alkoxy, hydroxycarbonyl, formyl, lower alkoxycarbonyl,lower alkylcarbonyloxy, lower alkoxycarbonyloxy, sugar, phosphosugar,O-quinone, substituted lower alkyl aminomethyl, or loweralkylcarbonylamino; and R^(Q) is optionally substituted carbocyclic,heterocyclic, or fused 2-, 3- or 4-ring heterocyclic; and b) exposingsaid subject to a unit dose of radiation.
 10. The method of claim 9,wherein W is R¹Y-L-C(O)—.
 11. The method according to claim 9 or 10,wherein R¹ is phenyl optionally substituted with from one to fivesubstituents independently selected from the group consisting of halo,lower alkyl, lower alkoxy, hydroxy, cyano, nitro, amino, halogenatedlower alkyl, halogenated lower alkoxy, formyl, lower alkyl carbonyl,hydroxycarbonyl, lower alkylcarbonyloxy, benzyloxy, optionallysubstituted piperazino, lower alkoxycarbonyl, and loweralkylcarbonylamino; a fused, 2-, 3-, or 4-ring heterocyclic systemoptionally substituted with one to five substituents independentlyselected from the group consisting of halo, lower alkyl, lower alkoxy,hydroxy, cyano, nitro, amino, halogenated lower alkyl, halogenated loweralkoxy, hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyloxy,and lower alkylcarbonylamino; 1- or 2-naphthyl optionally substitutedwith from one to four substituents independently selected from the groupconsisting of halo, lower alkyl, lower alkoxy, hydroxy, cyano, nitro,amino, halogenated lower alkyl, halogenated lower alkoxy,hydroxycarbonyl, lower alkoxycarbonyl, lower alkylcarbonyloxy, and loweralkylcarbonylamino; or a 5 or 6 membered heterocyclic ring containingone or two nitrogen atoms, which ring is optionally substituted with oneor two substituents selected from the group consisting of halo, loweralkyl, lower alkoxy, hydroxy, cyano, nitro, amino, halogenated loweralkyl, halogenated lower alkoxy, hydroxycarbonyl, lower alkoxycarbonyl,lower alkylcarbonyloxy, and lower alkylcarbonylamino.
 12. The methodaccording to claims 9 or 10, wherein R¹ is selected from the groupconsisting of O-quinone, semiquinone, fluorene, imidazole, triazole,pyridine, benzamide, nicotinamide, benzotriazine oxide, furan,thiophene, oxazole, or thiazole, where each of the aforementioned groupsmay be substituted or unsubstituted.
 13. The method of claim 9, whereinR¹ is aromatic.
 14. The method according to claim 9, wherein R¹ issubstituted with at least one carbonyl, amido, trifluoromethyl, halogen,nitro, nitroso, sulfonyl, sulfinyl, phosphoryl, or oxo group.
 15. Themethod according to claims 9 or 10, wherein R¹ is a nitro substitutedimidazol-1-yl or 3-nitro-1,2,4-triazol-1-yl group having the followingstructure

wherein R²⁰ is halo, alkyl, or substituted alkyl.
 16. The methodaccording to claim 9, wherein each L is independently a bond or-(T)_(n)-X—, wherein X is a O, S, —NH—, or a bond; T is independentlyCRR′; n is an integer from 1 to 3, and each of R and R′ is independentlyselected from hydrogen, lower alkyl, and substituted lower alkyl. 17.The method of claim 16, wherein WO— is selected from the groupconsisting of


18. The method according to claim 9 wherein steps a) and b) are appliedaccording to a treatment schedule effective to produce a synergisticanti-neoplastic effect. 19-56. (canceled)
 57. A method of treating aneoplasm comprising: a) administering to the subject a compound or apharmaceutically acceptable salt thereof having

wherein W is alkylC(O)—, or R¹Y-L-C(O)—, provided that when W isalkylC(O)—, at least one of R², R³, R⁴, R⁵, or R⁶ is nitro; L is a bondor linear alkylene (1-8) group, optionally substituted with lower alkylor substituted lower alkyl, wherein one or two methylene (—CH₂—) unitsof the linear alkylene group is optionally replaced with O, S or NH; Yis ═NO—, —N(H)O—, ═N—, —NR—, O, S, or a bond; R is H, alkyl, orsubstituted alkyl; R¹ is optionally substituted carbocyclic,heterocyclic, or fused 2-, 3- or 4-ring heterocyclic; R² is hydrogen,halo, lower alkyl, lower alkoxy, hydroxy, R^(Q)Y, R^(Q)Y-L-C(O)O—,cyano, nitro, amino, halogenated lower alkyl, halogenated lower alkoxy,hydroxycarbonyl, formyl, lower alkoxycarbonyl, lower alkoxycarbonyloxy,sugar, phosphosugar, tri lower alkylsilyl, lower alkylcarbonyloxy, loweralkylcarbonylamino, lower alkylcarbonyloxy methyl, substituted vinyl,1-hydroxy-2-nitroethyl, alkoxycarbonylethyl, aminocarbonyl,alkylcarbonyl, alkylcarbonyloxymethyl, benzoylmethyl,benzylcarbonyloxymethyl, or lower alkoxymethyl; R³ is hydrogen, halo,lower alkyl, lower alkoxy, hydroxy, R^(Q)Y-L-C(O)O—, cyano, nitro,amino, halogenated lower alkyl, halogenated lower alkoxy,hydroxycarbonyl, formyl, lower alkoxycarbonyl, lower alkoxycarbonyloxy,sugar, phosphosugar, CH₂NR⁷R⁸ (where each of R⁷ and R⁸ is independentlyH, alkyl of 1-6 carbons, optionally substituted phenyl, hydroxy loweralkyl, amino lower alkyl, or mono- or dialkylamino lower alkyl, or R⁷and R⁸ taken together with —N— represent a cyclic amino-), CH₂R⁹ (whereR⁹ is lower alkoxy, CN, amino lower alkoxy, mono- or di-lower alkylaminolower alkoxy, lower alkylthio, amino lower alkylthio, or mono- ordi-lower alkylamino lower alkylthio), NR¹⁰R¹¹ (where each of R¹⁰ and R¹¹is independently hydrogen, lower alkyl, phenyl, hydroxy lower alkyl, oramino lower alkyl, or R¹⁰ and R¹¹ taken together with —N— represent acyclic amino), dialkylamino alkyl, lower alkylcarbonyloxy, or loweralkylcarbonylamino; and R⁴ is hydrogen, halo, lower alkyl, lower alkoxy,hydroxy, R^(Q)Y-L-C(O)O—, cyano, nitro, amino, amino lower alkyl,halogenated lower alkyl, halogenated lower alkoxy, hydroxycarbonyl,formyl, lower alkoxycarbonyl, lower alkoxycarbonyloxy, sugar,phosphosugar, carbamoyloxy, lower alkylcarbonyloxy, or loweralkylcarbonylamino, or R⁴ together with R⁵ is methylenedioxy; R⁵ ishydrogen, halo, lower alkyl, lower alkoxy, hydroxy, R^(Q)Y-L-C(O)O—,cyano, nitro, amino, halogenated lower alkyl, halogenated lower alkoxy,hydroxycarbonyl, formyl, lower alkoxycarbonyl, lower alkylcarbonyloxy,lower alkoxycarbonyloxy, sugar, phosphosugar, or loweralkylcarbonylamino; R⁶ is hydrogen, halo, lower alkyl, lower alkoxy,hydroxy, R^(Q)Y-L-C(O)O—, cyano, nitro, amino, halogenated lower alkyl,halogenated lower alkoxy, hydroxycarbonyl, formyl, lower alkoxycarbonyl,lower alkylcarbonyloxy, lower alkoxycarbonyloxy, sugar, phosphosugar, orlower alkylcarbonylamino; and R^(Q) is optionally substitutedcarbocyclic, heterocyclic, or fused 2-, 3- or 4-ring heterocyclic; andb) exposing said subject to a unit dose of radiation.
 58. The method ofany one of claims 1, 9, 55 and 57, wherein the compound is administeredparenterally.
 59. The method of any one of claims 1, 9, 55 and 57,wherein the compound is administered intravenously.
 60. The method ofany one of claims 1, 9, 55 and 57, wherein the compound is administeredintramuscularly.
 61. The method of any one of claims 1, 9, 55 and 57,wherein the compound is administered orally.
 62. The method of any oneof claims 1, 9, 55 and 57, wherein the compound is administered in theform of a liposomal composition.